Tài liệu The production of english s clusters in initial position of english non majored students at can tho university

CAN THO UNIVERSITY SCHOOL OF EDUCATION ENGLISH EDUCATION DEPARTMENT THE PRODUCTION OF ENGLISH /S/- CLUSTERS IN INITIAL POSITION OF ENGLISH NON-MAJORED STUDENTS AT CAN THO UNIVERSITY B.A Thesis Field of study: English Language Teaching Supervisor: LE HUU LY, M.A Researcher: NGUYEN THI THUY NUONG Class: NN0652A2 Student’s code: 7062957 Can Tho, April 2010 Tóm tắt Bài nghiên cứu này được thực hiện với mục đích khảo sát về sự phát âm chùm phụ âm đầu [s] trong tiếng Anh của sinh viên trường Đại học Cần Thơ. Cụ thể hơn, nghiên cứu này nhằm tìm hiểu xem giới tính có ảnh hưởng đến sự phát âm chùm phụ âm đầu [s] của những người học tiếng Anh hay không, những lỗi phát âm nào thường đi kèm với từng phái và giữa những chùm phụ âm [s] gồm hai phụ âm và những chùm phụ âm [s] gồm ba phụ âm, loại nào khó phát âm chuẩn hơn. Đối tượng nghiên cứu được chọn một cách ngẫu nhiên trong các sinh viên trường Đại học Cần Thơ bao gồm hai mươi người: mười nam, mười nữ. Những sinh viên này sẽ đọc một danh sách những từ và những câu có chứa chùm phụ âm đầu [s] được soạn sẵn để tác giả thu âm lại. Sau đó, những phần thu âm này sẽ được phân tích bằng chương trình mô tả số liệu và chương trình ANOVA một chiều. Tất cả những người tham gia nghiên cứu đều có những lỗi sai về phát âm của các âm như [sp], [sk], [sl], [str], [st], [sm], [sn], [spr], [spl], [skr] và [skw]. Tuy nhiên, chỉ âm [sm] là có sự khác biệt lớn giữa nam sinh và nữ sinh. Có ba loại lỗi cơ bản những sinh viên này gặp phải khi phát âm chùm phụ âm đầu [s] đó là không phát âm âm [s] đầu tiên, không phát âm những phụ âm sau âm [s] và chêm thêm một nguyên âm sau âm [s]. Trong đó, không phát âm âm [s] là tiêu biểu nhất. Một kết quả khác được rút ra đó là các sinh viên gặp khó khăn khi phát âm những chùm phụ âm [s] gồm ba phụ âm hơn những chùm phụ âm [s] gồm hai phụ âm. Nhìn chung, nữ sinh có nhiều lỗi sai hơn nam sinh khi phát âm chùm phụ âm đầu khi đọc các từ này riêng lẻ nhưng khi những từ này được đặt trong ngữ cảnh, nữ sinh lại ít mắc lỗi về phát âm sai hơn nam sinh. i Abstract This study aims to investigate the production of English /s/- clusters in initial position in word list and in context of English non-majored students at CTU. More specifically, it were done to examine if gender significantly affects the EFL Vietnamese learners of productions [s]- cluster sounds and the types of mispronunciations associated with gender as well as to know whether tri-literal clusters are more difficult than bi-literal clusters based on the analysis of the recording. Twenty students including ten males and ten females from course 32 to 35 were randomly chosen to be the participants of this study. The data was collected while the participants were reading a word list and a text contained the target sounds. After that, the data were analyzed based on the descriptive statistics and One Way ANOVA program. All of mispronunciations of [s]-cluster sounds initial position such as [sp], [sk], [sl], [str], [st], [sm], [sn], [spr], [spl], [skr] and [skw]were observed but gender had a significant effect on pronouncing [sm] sounds in isolated words. There are three main type of mispronunciations that happened in the production of s-clusters which are unpronounced the pre-initial consonant [s], unpronounced the initial consonant like [p], [s], [t], [m], [n] [tr] of s-clusters and Epenthesis. Among them, the first type had a greatest percentage. Besides, another conclusion was drawn was that longer clusters would be more difficult for students of non English major at CTU to produce correctly. Overall, female students had more mispronunciations than their male counterparts for s-cluster sounds in word list. However, in context, they had fewer errors than male participants. ii ACKNOWLEDGEMENT During implementing this thesis, I have received much help and contribution from many people to whom I would like to express my deep gratitude. First and foremost, my thesis hardly finished without valuable encouragement, advice, comment from my supervisor, Mr Le Huu Ly. I could not forget his enthusiasm to give me such a great help so that I could finally finish my thesis. Second, my regards are respectively sent to all the teachers of the English Department for their encouragement and guidance. Especially, my sincere gratitude is sent to Ms. Hong Thi Thanh Truc, an English teacher in the English Department, and Ms. Elizabeth Hollingsworth, a native speaker from America for helping me detect the participants' mispronunciations. Also, I would like to thank all of the participants and some of my friends, especially Nguyen Ngoc Cat Khuyen and Le Thi Van for their help during the time I collected the data for this study. And I would like to acknowledge Ms. Ngo Thi Trang Thao who gave me useful instructions to analyse the data using SPSS program. Next, I would like to send my special thanks to my close friends for being by my side and giving much encouragement to finish this thesis. Last but not least, I really want to thank my family and my boyfriend whose encouragement was very meaningful and very important to me during the time of doing this research. iii TABLE OF CONTENTS ABSTRACT (Vietnamese) ................................................................................................... i ABSTRACT (English) .......................................................................................................... ii ACKNOWLEGMENT .......................................................................................................... iii LIST OF TABLES................................................................................................................. iv LIST OF FIRGUGES ............................................................................................................ vi Chapter 1 - INTRODUCTION ............................................................................................. 1 1.1 General statement of problem .................................................................................. 1 1.1.1 The Sonority Sequencing Principle ................................................................. 2 1.1.2 The Markedness Differential Hypothesis........................................................ 3 1.2 Background of the study........................................................................................... 3 1.2.1 Initial consonant clusters. ................................................................................. 3 1.2.2 The initial s- clusters ......................................................................................... 4  The initial bi-literal s- clusters ............................................................... 5  The initial tri-literal s- clusters............................................................... 5 1.2.3 Problems for pronouncing English /s/-clusters. .............................................. 6 1.3 Research Aim............................................................................................................ 6 1.4 The organization of the study................................................................................... 6 Chapter 2 – LITERATURE REVIEW ................................................................................. 7 2.1 Studies that examined the production of English initial s-clusters in some countries around the word .......................................................................... 7 2.2 Studies about English pronunciation of Vietnamese learners ........................... 12 2.3 Studies that investigated gender differences in language learning ................... 13 Chapter 3 – METHODOLOGY............................................................................................ 15 3.1 RATIONAL......................................................................................................... 15 3.2 RESEARCH QUESTIONS ................................................................................ 15 3.3 HYPOTHESIS .................................................................................................... 15 3.4 PARTICIPANTS.................................................................................................. 16 3.5 RESEARCH INSTRUMENTS ........................................................................... 16 3.6 RECORDING PROCEDURE ............................................................................. 17 3.7 CODING............................................................................................................... 17 Chapter 4 – RESULTS .......................................................................................................... 18 iv 4.1 Gender differences in the Production of English /s/- clusters in initial position of English non-majored students at CTU.............................. 18 4.1.1 Descriptive statistics for [sp] in word list and in context........................... 19 4.1.2 Descriptive statistics for [sk] in word list and in context.......................... 20 4.1.3 Descriptive statistics for [sn] in word list and in context........................... 21 4.1.4 Descriptive statistics for [sw] in word list and in context.......................... 22 4.1.5 Descriptive statistics for [st] in word list and in context............................ 23 4.1.6 Descriptive statistics for [sm] in word list and in context.......................... 24 4.1.7 Descriptive statistics for [sl] in word list and in context............................ 25 4.1.8 Descriptive statistics for [spr] in word list and in context ......................... 26 4.1.9 Descriptive statistics for [spl] in word list and in context.......................... 27 4.1.10 Descriptive statistics for [skr] in word list and in context ....................... 28 4.1.11 Descriptive statistics for [str] in word list and in context ........................ 29 4.1.12 Descriptive statistics for [skw] in word list and in context...................... 29 4.2. Types of mispronunciations of s-cluster sounds in initial position ............................. 30 4.3. Analysis of bi-literal s-clusters /sC/ versus tri-literal s-clusters /sCC/ clusters.......... 32 4.3.1 Cluster /sp/ vs. / spC/.............................................................................................. 33 4.3.2 Cluster /sk/ vs. / skr/, /skw/ .................................................................................... 34 4.3.3 Cluster /st/ and / str/................................................................................................ 35 Chapter 5 – DISCUSSION, IMPLICATIONS, LIMITATIONS AND CONCLUSION 5.1 Discussion ................................................................................................................... 37 5.1.1 Pronunciation of English /s/- clusters in initial position between males and females ............................................................................................................. 37 5.1.2 Types of mispronunciations of s-cluster sounds in initial position................ 39 5.1.3 Bi-literal s-clusters /sC/ versus tri-literal s-clusters /sCC/............................. 41 5.2 Conclusion ................................................................................................................... 41 5.3 Limitations of the research.......................................................................................... 42 5.4 Implications ................................................................................................................. 42 5.5 Suggestion for further research................................................................................... 43 REFERENCES.....................................................................................................................viii APPENDIX ............................................................................................................................xii v List of Tables page Table 1.1: Two-consonant clusters with pre-initial s .......................................................... 5 Table 4.1: Number of errors for [s]-clusters ........................................................................ 18 Table 4.2: Descriptive statistics for [sp] in word list and in context .................................. 19 Table 4.3: Levene’s Result for [sp] in isolated word list and in context............................ 19 Table 4.4: Descriptive statistics for [sk] in word list and in context .................................. 20 Table 4.5: Levene’s Result for [sk] in word list and in context.......................................... 20 Table 4.6: Descriptive statistics for [sn] in word list and in context .................................. 21 Table 4.6: Descriptive statistics for [sn] in word list and in context .................................. 21 Table 4.8: Descriptive statistics for [sw] in word list and in context ................................. 22 Table 4.9: Levene’s Result for [sw] in word list and in context........................................ 22 Table 4.10: Descriptive statistics for [st] in word list and in context................................. 23 Table 4.11: Levene’s Result for [st] in word list and in context......................................... 23 Table 4.12: Descriptive statistics for [sm] in word list and in context............................... 24 Table 4.13: Levene’s Result for [sm] in word list and in context ...................................... 24 Table 4.14: Descriptive statistics for [sl] in word list and in context................................. 25 Table 4.15: Levene’s Result for [sl] in word list and in context......................................... 25 Table 4.16: Descriptive statistics for [spr] in word list and in context............................... 26 Table 4.17: Levene’s Result for [spr] in word list and in context ...................................... 26 Table 4.18: Descriptive statistics for [spl] in word list and in context............................... 27 Table 4.19: Levene’s Result for [spl] in word list and in context ...................................... 27 Table 4.20: Descriptive statistics for [skr] in word list and in context............................... 28 Table 4.21: Levene’s Result for [skr] in word list and in context ...................................... 28 Table 4.22: Descriptive statistics for [str] in word list and in context................................ 29 Table 4.23: Levene’s Result for [str] in word list and in context ....................................... 29 Table 4.24: Descriptive statistics for [skw] in word list and in context ............................. 29 Table 4.25: Levene’s Result for [skw] in word list and in context..................................... 30 Table 4.26: Types of mispronunciations of s-cluster sounds ............................................. 31 Table 4.27: Number of errors of tri-literal s-clusters and bi-literal s-clusters made by participants in isolated words............................................ 32 Table 4.28: Number of errors of cluster /sp/ vs. /spC/ by participants in isolated words and in context................................................... 34 vi List of Firgures Figure 4.1: Total rates of errors of tri-literal s-clusters and bi-literal s-clusters made by participants in isolated words ......................33 Figure 4.2: Total rates of errors of cluster /sp/ vs. /spC/ by participants in isolated words and in context........................................34 Figure 4.3: Total rates of errors of cluster /sk/ vs. /skC/ by participants in isolated words and in context.............................................35 Figure 4.4: Total rates of errors of cluster /st/ and /str/ by participants in isolated words and in context............................................36 vii The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. Chapter One INTRODUCTION There are four parts in this chapter. The first part is General statement of problem, which explains the reason why this research was carried out and introduces some related theories. The second part is the background of the study, which presents what s-clusters are. The next part is the research aims of this paper. The last part will show the organization of this thesis. 1.1 General statement of problem English is a global language. So, the number of English learners around the world has been increasing tremendously. In Vietnam, people are rushing to foreign language centers to learn English because there is a big need for schooling and jobs opportunities. However, there are many factors which influence language learners’ pronunciation. According to Hinofitis and Baily (1980), pronunciation is one of the most important things of studying second language because it affects learners' communication competence. Szynalski and Wojcik (2002) also stated that pronunciation is the first and most important aspect that speakers pay attention to when having a conversation. Knowing grammar and vocabulary is important but it becomes useless if the speaker is unable to pronounce words correctly. However, learning pronunciation is not easy for many people because of different reasons. Nguyen (2007) mentioned three main reasons. First, it may be influenced by learners' mother tongue. Second, it may be because of the study environment and third, it is learners' motivation in studying pronunciation. Like some other languages, Vietnamese has phonetics that keeps native learners from pronouncing English like native speakers. The limitation of Vietnamese word-initial consonantal cluster sounds and the frequency of English initial clusters errors, which are made by many Vietnamese learners, have caught attention to this area of this topic. 1 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. At Can Tho University, all undergraduates of English non-major have to finish three courses of. The materials for these courses are REWARD ELEMENTARY books which supply students basic knowledge about English grammar, pronunciation and vocabulary. However, in non-majored classes, because of limited time of 4 periods per week in class, lessons usually focus on grammar and reading and therefore, teachers do not much focus on teaching English pronunciation or correcting students’ pronunciation mistakes. Furthermore, in these courses of General English, students study different majors in different schools, they have different English levels and English is just a subsidiary subject. Thus, having problems in pronouncing English is understandable. This paper will investigate the difficulties of English non-majored students at Can Tho University when dealing with English initial s-clusters. This is considered one of the most significant problematic features of English learners. The finding of this research will hopefully help English non-majored students at Can Tho University to become aware of their systematic errors and carefully try to produce English initial s-clusters correctly. 1.1.1 The Sonority Sequencing Principle There is a universal (in all languages) tendency for sonority to gradually increase in the onset, and decrease in the coda. This is called the Sonority Sequencing Principle. The Sonority Sequencing Principle was identified in linguistics research during the last 20 years or so. It dictates that onsets (word-initial sounds) must rise in sonority and codas (ending sounds) must fall in sonority. Sonority is the inherent loudness of sounds relative to one another. Many syllables of English conform to this universal tendency. However, some do not. In particular those consonant clusters that start with /s/ slightly violate the universal tendency. For this reason, L2 learners of English often have difficulty with these clusters. They tend to make them more natural by inserting, or deleting segments: 2 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. 1.1.2 The Markedness Differential Hypothesis Ecknam (1993) based on a theory of markedness in phonology to hypothesize that more frequent sounds in many languages are called unmarked while the sounds which are not popularly used among languages in the world are marked sounds. Gass & Selinker (2001) claim that sounds related to voicing contrast in initial, medial and final position are marked. In this case, Vietnamese speakers of English may find it challenging to pronounce some s-clusters in initial position because they are not pronounced in Vietnamese. 1.2 Background of the study The pronunciation of English syllable codas by second language (L2 learners of English, especially whose native languages (L1s) do not have phonetic features similar to English, has received much attention in L2 research. Vietnamese, for example, does not have consonant clusters which are allowed in English in various word-positions. Vietnamese L2 learners of English have been found to have problems with pronouncing English consonant clusters. 1.2.1 Initial consonant clusters Cluster formation is one of the most interesting topics of various aspects of a language’s phonology. This is attested in the variety of cluster formation in language acquisition (L1), language learning (L2), as well as the dialectal variants of the norm. The fundamental claim governing cluster formation is that the bigger the distance between the members of a cluster on the sonority scale is, the better structured the cluster is (Clements, 1983). A consonant cluster is described as being two or more adjacent consonants in the same syllable (e.g., /br/ in brush, /skw/ in square, and /nt/ in paint). The consonants that constitute a cluster are referred to as cluster elements in this paper. Consonant clusters are very commonly used in English words. McLeod et al. (2001) reported that one third of single syllables in English start with word-initial clusters. Many English words end in consonant clusters due to word-final grammatical morphological structures which can, but do not always, create word-final clusters. For example, the phonemes /s, z, t, d/ are added in word final position for the possessive form of pronouns (e.g, it’s, mum’s), plural 3 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. nouns (e.g., dogs, lips) while the phonemes /sp, sl,../ in “speak”, “slang” are consonant clusters in initial- position. Concerning the possible combinations of initial consonants, Brinton (2000, p. 55) lists the following non-permissible sequences of consonants: - stop + stop, such as in /pt/; - stop + nasal, such as in /pn/; - nasal + stop, such as in /np/; - stop + fricative, such as in /ts/; - fricative + stop, such as in /ft/, except where the fricative is /s/ A classification of the possible English clusters taken from Avery & Ehrlich (1992, p.55-58) is provided below together with their example of each cluster: (1) initial bi-literal (two-consonant) clusters beginning with a stop include /pl, kl, pr, tr, kr, tw, kw, bl, gl, br, dr, gr/ (2) initial bi-literal clusters beginning with a fricative include /fl, sl, fr, Tr, Sr, sw, sp, st, sk, sm, sn, sf/ (3) initial tri-literal (three-consonant) clusters include /spl, spr, str, skr, skw/ For example: splice, spring, string, screw, squirt... According to Rauber (2002), the phoneme /s/ occurs in initial position in the three languages (English, Portuguese and Spanish), but it only forms word-initial clusters in English. Hence, it is difficult for English learners to study how to pronounce s-clusters correctly. 1.2.2 The initial s- clusters Sequences of two or three consonants are called clusters, which constitute an important aspect of restrictions on syllable types, since there is a limited number of possible combinations of segments in both initial and final positions. Clusters with initial /s/, for instance, are the only instances of onsets where the second consonant may be an obstruent and where the onset may be formed by three consonants instead of one or two. In order to represent the particular category of /s/ clusters, Selkirk (1982) provides an auxiliary template, considering that “/s/ plus obstruent may qualify as a single obstruent in English”. 4 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University.  The initial bi-literal s- clusters In the book “English Phonetics and Phonology”, Roach (2008, 78) wrote “One sort is composed of s followed by one of a set of about eleven consonants”. It was a combination of [s] with one possible consonant, so it was called [sC]. He listed some examples such as “sting”, sway, smoke. The /s/ in these clusters is called the pre-initial consonant and the other consonants (t, w, m in the above examples) the initial consonant. These clusters are showed in table below. Table 1.1: Two-consonant clusters with pre-initial /s/ Initial Pre-s + e.g p t k b spin stik skin - d g - f θ s - sfiə - - ∫ h - v ð - - - z ʒ m n η - - smel snou - Roach (2008) also noted that two-consonant clusters of s plus l, w, j were also possible (e.g slip, swiη, sju:).  The initial tri-literal s- clusters Besides, Roach (2008) also mentioned about – They are [sCC]. Example of three-consonant clusters are “split” /split/, “stream” /stri:m/, “square”/skweə/. The s is the pre-initial consonant, the p, t and k that follow s in the three example words are the initial consonant and the l, r and k are post-initial. These clusters are showed in table below. POST-INITIAL l S PLUS INITIAL r w j p splay spray --- spew t --- string --- stew k sclerosis screen 5 squeak skewer The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. However, in their studies, Rebello (1997) and Carlisle (1997, 1992, 1997) stated that there are six English two-segment /s/- clusters (/sp, st, sk, sm, sn, sl/), and five threesegment /s/-clusters (/spr, str, skr, spl, skw/). I follow this point of view to do my study. 1.2.3 Problems for pronouncing English /s/-clusters. According to Selkirk (1982), the /s/-clusters are equally problematic for theoretical accounts of English and other languages with [s]-clusters. First, [s] stop clusters violate the sonority sequencing principle, in that they have a falling sonority slope. Secondly, clusters [sl-], [sn-] and [st-] violate a phonotactic constraint on initial clusters in English which prohibits homorganic clusters. Thirdly, [s] is the only sound that may be followed by a nasal or a stop in initial clusters. Finally, [s] is the only sound that may occur at the beginning of a three-element cluster such as [str-], [spr-], [skw-] or [spl]. All these facts reveal the special status of /s/-clusters. 1.3 Research Aim: The purpose of this research is to examine the production of s- clusters in initial position of English non-majored students at Can Tho University (CTU). Especially, this study aims to investigate if male and female speakers pronounce those sounds significantly differently. 1.4 The organization of the study This thesis is divided into five chapters. Chapter 1 introduces the importance of pronunciation in studying languages and presents some related theories of this study. Chapter 2 summarizes some studies that examined the production of English initial sclusters in some countries and some other studies about Vietnamese EFL learners' pronunciation of the target sounds. Chapter 3 is about the methodology through which the study is conducted. Chapter 4 presents the results of the study. And, chapter 5 discusses the research findings, limitations and conclusion. 6 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. Chapter Two Literature Review This chapter is categorized into three parts. Part 1 summaries some studies that examined the production of English initial s-clusters in some countries. Part 2 presents some other studies about Vietnamese EFL learners' pronunciation of the target sounds. In addition, part 3 includes some studies that investigated gender differences in language learning 1. Studies that examined the production of English initial s-clusters in some countries around the world There have been many studies about the production of English initial s-clusters in some countries around the world such as in Australia, in Brazil, in China and so on. Some of those are mentioned below. Silveira (2002) did a research to investigate the relationship between perception and production in the acquisition of word-initial /s/ clusters in the interlanguage of Brazilians learning English as a foreign language. While testing this relationship, he also contributed to the controversial issue of the role of markedness and the first language (L1) interference on the production of word-initial /s/ cluster. In addition to the interface between perception and production, other factors that might influence both mental processes such as faulty perception and L1 interference, or a combination of these factors, were taken into account. This was tested by collecting data assessing subjects’ perception and production of English initial /s/ clusters in two different sessions: production test and perception test. In production test, the subjects were required to record the translation from Portuguese into English of 14 sentences, where the English 7 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. version was expected to contain at least one word with an initial /s/ cluster. The perception test was carried out two weeks after the production test. The subjects received a short training by repeating s-cluster words provided by an American native speaker. Immediately after the training, they were tested again by listening to the tape containing the 26 sets of sentences. The results partially supported studies which proposed that perception influenced production. There was also support for the power of L1 interference over Markedness and Universal Canonical Syllable Structure. Epenthesis was the strategy of syllable simplification present in all cluster types. Some subjects, though, resorted to a short epenthetic vowel (/I/), thus indicating that they might be developing a separate category for initial /s/ clusters. Like Silveira, Cardoso, French & John (2008) also based on a theory of markedness to do a research to investigate the effects of markedness and input frequency in the development of English homorganic /sl/, /sn/ and /st/ among Brazilian Portuguese native speakers learning English in a classroom environment. It provided a multidisciplinary analysis for the acquisition of /s/ + consonant onset clusters (sC) in second language phonology, adopting a variationist approach for data collection and analysis that included from a variety of linguistic disciplines, including theoretical phonology, psycholinguistics, second language acquisition, and sociolinguistics. The results of an oral production study indicated that English learners acquire /sl/ and /sn/ clusters earlier than the most marked /st/, corroborating the hypothesis that markedness, and not input frequency, determines the order of acquisition of bi-literal s-clusters in second language production. To consider the acquisition of /s/-clusters relative to other clusters of English, many studies were done by Smit (1973), Barlow (1997), Gierut, (1999). In Smit’s study (1973), the errors on word-initial consonant clusters made by children in the Iowa were tabulated by age range and frequency. The error data show considerable support in the 8 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. acquisition of clusters: the youngest children show cluster reduction, somewhat older children show cluster preservation but with errors on one or more of the cluster elements, and the oldest children generally show correct production. These stages extended to three-element clusters as well. Typical cluster reduction errors were (a) reduction to the obstruent in obstruent-plus-approximant clusters and (b) reduction to the second element in /s/-clusters. When clusters were preserved, but one member was in error, the error was typically the same as for the singleton consonant. Cluster errors are discussed in terms of theories of phonologic development, including open genetic programs and feature geometry. Meanwhile, Barlow (1997) stated that normal and disordered phonological development have evidenced an asymmetry in the development of clusters in English, particularly the s-clusters relative to other clusters. She explained that this asymmetry was found by appealing to differing structural representation. Some clusters may be represented as a complex onset, while others like s-clusters may be represented as an adjunct of clusters. Having the same idea about s-clusters as adjuncts with Barlow, Giuret (1999) did a research on a presumed universal that governs the permissible sequences of consonants within syllables. In two single-subject experiments, he evaluated this principle as applied to the acquisition of onset clusters and adjuncts by children exhibiting functional phonological delays. Experiment 1 tested the hypothesis that children abide by the Sonority Sequencing Principle (a universal tendency for sonority to gradually increase in the onset, and decrease in the coda) in development, such that the occurrence and use of marked true clusters implies unmarked clusters. Others who were taught unmarked clusters exhibited limited learning characteristic of within-class generalization, with apparent gaps in sonority sequencing. Experiment 2 examined the role of adjunct sequences /sp, st, sk/, whose markedness status is questionable given their violation of the Sonority Sequencing Principle. Results indicated that children learned adjuncts consistent with patterns of within-class generalization, thereby supporting the view that these sequences are unmarked in structure. 9 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. Another study was done by Rauber (2002) to examine the production of English initial /s/ clusters by Portuguese and Spanish EFL Speakers. In order to compare the production of speakers of both native languages the same corpus was used. By basing on the analysis on the Markedness Differential Hypothesis, he tried to confirm whether the difference in the structure of Portuguese and Spanish syllables results in greater difficulties in different /s/ clusters in different environments or not. The participants chosen for this experiment were nine native Spanish speakers from Argentina and ten native Portuguese speakers from Brazil. They were asked to read and were recorded the sentences done by the researcher. After analyzing, the results revealed that epenthesis (the addition of an extra vowel) to the initial clusters is the usual strategy for dealing with syllable structure difficulty, which can be a result of native language interference and linguistic universals. He concluded that learners’ difficulties established by the Markedness Differential Hypothesis and the Structural Conformity Hypothesis were borne out, since longer initial /s/ clusters caused a greater rate of epenthesis than shorter ones for both Spanish and Portuguese speakers. Although few studies have investigated the phonological context where errors occur, another aspect that should be taken into account regarding epenthesis and consonant deletion for syllable simplification is the influence of environment in Spanish/English and Portuguese/English interphonology. Carlisle carried out several studies involving native Spanish-speaking learners of English as a second language, who were asked to read a number of topically unrelated and randomly ordered sentences containing initial /s/-clusters in two types of environment. Carlisle (1991) examined epenthesis before three word-initial onsets in English: /sk/, /st/ and /sp/; Carlisle (1991, 1992, ) investigated the frequency of epenthesis before the word-initial onsets /sl/ and /st/; Carlisle (1992) investigated the production of epenthesis before the word-initial onsets /sl/, /sm/ and /sn/; and Carlisle (1997) compared the production of /sC/ vs. /sCC/ clusters. All the studies controlled the environments before the onsets and the sonority 10 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. relationships among the consonants in the onsets. His findings in the four studies revealed that vowel epenthesis was significantly more frequent after consonants than after vowels. Concerning the variable length examined in Carlisle (1997), his findings revealed that triliteral clusters, whose structure is more marked, were more frequently modified than biliteral clusters, confirming that language universals “influence the structuring of interlanguage phonology” (p. 327). Similar results were obtained by Abrahamsson (1997, 1999). In his longitudinal study, he investigated a male native speaker of Spanish from Bolivia, who was a guest student at Stockholm University, and an absolute beginner of Swedish. Data were collected during eight months, and consisted of recordings where the participant and a native speaker of Swedish talked about various topics. Besides free speech, activities such as object or picture description and picture story retelling were adopted to elicit specific grammatical/discourse patterns and communication strategies. His findings corroborated those of Carlisle, since longer clusters were more frequently modified, and consonantal environments caused more epenthesis than silence and vocalic environments. Concerning the longitudinal aspect of the study, Abrahamsson concluded that the frequency of epenthesis increased in the beginning of the acquisition process, since the participant was starting to develop his target language fluency. The studies above show that acquiring the s-clusters in initial position is not an easy task for many learners of English in some parts of the world. Mostly, difficulties in pronouncing [s]-cluster sounds established by the Markedness Differential Hypothesis. Epenthesis was a popular error among Brazilians, Portuguese and Spanish when pronouncing s-cluster sounds (Rauber,2002). They inserted a vowel like [ə] or [i] after the sound [s] to make s-clusters more easily to produce. In the context of Vietnam, problems about the acquisition of English pronunciation have not been paid enough attention, as they should be. It is the fact that Vietnamese learners of English have much 11 The Production of English /s/- clusters in initial position of English non-majored students at Can Tho University. difficulty in English pronunciation. Similarly, these s-cluster sounds also cause difficulties for English learners that were specified in some studies below. 2. Studies about English pronunciation of Vietnamese learners Whereas much research with a focus on syllable codas has been done on English as a second language (ESL), native speakers of Portuguese, Arabic, and Chinese, not many researchers have examined native speakers of Vietnamese in this regard. Not until the 1980s, when there was an influx of Vietnamese immigrants to the United States after the Vietnam War, did researchers such as Sato (1984, 1985) and Benson (1986) begin to investigate the L2 phonology of Vietnamese immigrants upon noticing their erroneous production of syllable onsets and codas. Findings from these studies have confirmed that consonant clusters are one area of difficulty Vietnamese ESL learners have. In this regard, Hwa-Froelich, Hodson, and Edwards (2002) did a rather comprehensive investigation into Vietnamese phonology, comparing and contrasting its phonological characteristics with English, in order to see how these features may be carried by Vietnamese learners into their L2 English phonology. They also suggested that Vietnamese learners might have problems with both English consonant clusters in initial position and final position. Tang (2007) used survey and ethnographic methods to provide a linguistic basis for promoting first language maintenance of Vietnamese in a larger United States context and to encourage future research in language acquisition of Vietnamese-English speakers. This article also presented the social and linguistic issues related to language maintenance among Vietnamese. Although Vietnamese and English share certain sounds, there are multiple consonant sounds specific to each language. Especially, Tang (2007) listed consonant clusters in initial position that are absolutely foreign to the Vietnamese language such as s-clusters (sk, scr, sm,sn...), r-clusters (br, cr, dr...), l-clusters (bl,cl...) and so on. However, this material is quite detailed and should be appreciated. It is easily seen from this data that English have a number of consonants and consonant clusters that do not exist in Vietnamese rather than vice versa. As a result, he concluded that pronouncing English consonant clusters properly is one of the most difficult things that learners have to face from the beginning. 12