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Chapter 1
INTRODUCTION
1.1. RATIONALE
Every language learner has a wish of achieving the most efficiency in
communication. To do that, learners have to pay much attention to using the
language as well as pronouncing them correctly. As far as the aspect of
connected speech is concerned, it is not easy for Vietnamese learners to
perform English sounds, especially English stops as well as to perceive and to
comprehend them in conversations. They meet so many difficulties in
pronunciation. One of those is caused by the influence of their mother tongue
on their language learning because each language has its own rules and
phonetic system which may cause a lot of obstacles to learners in practicing
and performing them correctly. More importantly, most of the learners do not
pay attention to how to pronounce English stops in the initial, middle or final
positions, i.e. devoicing them in the initial position, releasing them in final
position, connecting them, lengthening or shortening the vowels followed by
an English stop, etc. Accordingly, they may get trouble with speaking and
listening to native speakers.
Besides, the learners and teachers’ method as well as attitude towards
pronunciation teaching and learning are not good enough. From my own
experience and observation in classrooms of English in Tuy Hoa Industrial
College, the students are found to have few opportunities of practicing to
improve their pronunciation skill because the teachers tend to equip them with
knowledge of grammar and vocabulary without paying much attention to
practicing pronunciation. They tend to de-emphasize pronunciation in
language courses. Furthermore, their tests and examinations focus mainly on


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- Suggest some solutions to mistake correction in pronunciation of
English stops experienced by the students as well as activities to enhance their
performance of these sounds.
1.2.3. Questions of the study
To achieve the aims and objectives mentioned above, this study tries to
answer the following questions.
1. What are the similarities and differences between English and
Vietnamese stops?
2. What are common mistakes made by students at Tuy Hoa Industrial
College in performing English stops?
3. What causes those mistakes?
4. What are the effective ways and activities that teachers of English
at colleges can apply to correct and improve students’
pronunciation of English stops?
1.3. THE SCOPE OF THE STUDY
This study just focuses on examining the perception and production of
English stops / p, b, t, d, k,

/ by students. In this study, the students at Tuy

Hoa Industrial College would be chosen as the representative informants.
1.4. DEFINITION OF TERMS
Stops or plosives are consonant sounds produced by stopping the
airflow in the vocal tract then separating rapidly. The term “plosive” is
reserved for oral (non- nasal) stops. Plosives include / p, b, t, d, k,
20:130]


same due to their developmental changes in the brain. In order to achieve the
goal of pronouncing as closely as native speakers, the learners need to be
provided good knowledge of the English sounds. This may possibly
contribute to the fact that apart from the course-books designed for only
speech training with little information on how a speech sound is produced,
most writers have discussed the articulation of speech sounds with details,
especially the issues of English stops.
In an early study of English speech sounds, Connor (1973) dealt with
the stops by starting with the English phonemes rather than concrete sounds.
In his study, the phonemes were focused on the variety of sounds by which
they are realized. In a practical view, Roach (1983) made a contrast between
the minimal pairs of English stops which can help the learners have
distinction between /p/ and /b/, /t/ and /d/, and / k/ and / /. He also studied
their distribution and variants.
In a view of error analysis, Ladefoged (1982) introduced some
important general phonetic notions of English stops. He analyzed specific
mistakes of English stops which foreign learners often encounter and showed
how to produce these sounds correctly in particular cases.


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In the aspect of teaching pronunciation, Kenworthy (1992) focused on
the specific problems encountered by speakers of Arabic, Chinese, French,
German, etc. And he also examined the areas of difficulty in terms of
learning and teaching strategies. However, in this study, he has not addressed
the problems which Vietnamese learners often meet in pronouncing English
stops.
Research on phonetics and phonology by Carr (1999) described
English stops and gave the detailed distinction between aspirated and

pulmonic egressive, that is, with air flowing outward from the lungs.
The complete articulation of a pulmonic egressive, plosive or stop
consonant consists of three stages:
1. The closing stage, during which the articulating organs move together in
order to form the obstruction; in this stage, there is often an on-glide or
transition audible in a preceding sound segment and visible in an acoustic
analysis as a characteristic curve of the formants of the preceding sound.
2. The holding or compression stage, during which lung action compresses
the air behind the closure; this stage may or may not be accompanied by
voice, i.e., vibration of the vocal cords.
3. The release or explosion stage, during which the organs forming the
obstruction part rapidly, allowing the compressed air to escape abruptly; if
stage (2) is voiced, the vocal cord vibration may continue in stage (3); if
stage (2) is voiceless, stage (3) may also be voiceless (aspiration) before
silence or before the onset of voice ( as for a following vowel), or stage (3)
may coincide with the onset of vocal cord vibration, as when a voiceless
plosive is followed without intervening aspiration by a vowel; again, an


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off-glide or transition associates the plosive with a following sound.
[8:150]
The description of the production mechanism above is just a general
one because each sound in this group will have different phonetic variants
when it is distributed in different positions in a word.
2.2.2. Contrastive analysis of stop consonants in English and Vietnamese
Apart from using knowledge of our students and our ears in order to be
aware of their pronunciation problems, it is also useful to have some prior
knowledge of what elements of English phonetics and phonology are likely to

/ /

Basically speaking, both English and Vietnamese stops have the same
production mechanism. They are divided into three pairs, as we have seen,
according to the manner of articulation. Members of each pair can be
distinguished on voiceless and voiced features.


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2.2.2.2. Differences
As mentioned above, the production mechanism of the stops in English
and Vietnamese is similar in general; however when distributed in different
contexts of words or in connected speech, English stops are affected by the
surrounding sounds and undergo some changes. As a result, each stop in
English has it own phonetic variants, which foreign learners of English,
especially Vietnamese learners hardly recognize in speaking and listening.
Firstly, in Vietnamese, final stops neither have a release burst nor have
a nasal release whereas English final stops are often produced with these
phonetic features (with audible or no audible release).
Secondly, the English and Vietnamese stops are distributed differently
due to the phonetic systems of both languages as described in Table 2.2 and
Table 2.3. Examine Table 2.2 and Table 2.3 below we can have some
comments as follows:
English stops are distributed in different positions in words, while
Vietnamese does not have a voiceless stop [p] in the initial position.
Therefore, Vietnamese learners may fail to correctly pronounce the voiceless
stops [p] in this position. They may produce the word “pen” like “Ben”
because they might not pay attention to the force of articulation. /p/ is
produced with a stronger breath effort than /b/.

lopping

lobbing

bitter

bidder

postcard

beginning

final

rip

rib

writ

rid

risk

rig

Position


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-

-

-

-

-

-

final

đập

-

tắt

-

tắc

-

position

In Vietnamese /p/, /t/, and /k/ appear at the end of words without

Allophones

[p]

/t/

[p ]

[t]
[ ]

/k/

[k]

[k ]

Figure 2.1 English voiceless stop phonemes
(Adapted from [6:38])
Another feature that makes English stops different from Vietnamese
stops is consonant cluster. “Consonant cluster is a group of consonants with
no intervening vowel”[10]. In English consonant clusters such as [pl], [bl],
[dr], [ l] … are very popular. It is quite difficult for Vietnamese learners of
English to pronounce English consonant clusters because of no habit of
pronouncing these sounds in their mother tongue. They tend to insert the
vowel /ʋ/ after / p, b, d, k,

/ followed by / l, r /. For example, they may

pronounce the word “class” [klas] like [kʋlas].

possible syllable contains a nucleus only. A syllable may or may not have an
onset and a coda.
The general structure of a syllable consists of the following segments
which are shown in Figure 2.1.
σ
O

R
N

c(consonant)

v (vowel)

Co

c (consonant)

Figure 2.2 Internal structure of a syllable
(Adapted from [12])


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Onset (obligatory in some languages, optional or even restricted in
others) is the beginning sounds of the syllable; the ones preceding the
nucleus. These are always consonants in English. The nucleus is a vowel in
most cases, although the consonants [ r ], [ l ], [ m ], [ n ], and the velar nasal
(the 'ng' sound) can also be the nucleus of a syllable. In the following words,
the onset is in bold; the rest underlined: card, drop, strain. If a word contains



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Unlike English, Vietnamese is a monosyllabic language. Syllables
often coincide with words. They consist of two mandatory components: a
tone and a nuclear vowel. The syllables may also contain two optional
components: an initial consonant and a final consonant or semivowel. The
initial consonant may or may not be accompanied by a secondary labial
articulation. Furthermore, O consists of only one consonant, whereas in
English, O may consists of more than one consonant (clusters). In addition,
there are clear-cut borderlines between words and each syllable ends without
releasing the final sounds, which could raise difficulties to Vietnamese
learners of English. They may tend to delete the final sounds and may forget
connecting words in natural speech. The possible negative transfer of the
phonetic features stops in Vietnamese syllabic structure is one of the serious
causes which make Vietnamese learners of English take no notice of the
assimilation and the liaison i.e. the linking of a final consonant in the
preceding word to the initial vowel of the following word. In term of fluency,
they may not be successful in performing as well as perceiving sounds in
connected speech.
2.3. SUMMARY
The chapter reviews some previous studies which are related to the
topic of the research. In addition, the contrastive analysis between English
and Vietnamese stops in terms of phonetic features in consonant systems and
syllabic structure gives an overview of the differences of stops in the two
language systems which can interfere second learners’ language learning
process, from which the researcher could draw some assumptions of potential
mistakes that Vietnamese learners of English may have.


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3. They may fail to correctly pronounce vowels followed by a voiced or
voiceless English stops.
3. 3. SUBJECT SELECTION AND DESCRIPTION
The subjects involved in the research are the first year students selected
randomly from the classes at Tuy Hoa Industrial College with groups of
different levels. The informants are non-specializing English students who are
required of having studied English for at least three years at high schools.
This subject selection of the study is based on the following reasons.
Firstly, according to the school syllabus, non-specializing English
students only study English in the first, the second and the third semesters.
Therefore, it is necessary to carry out the investigation into the first year
students.
Secondly, the informants were divided into groups of different levels
according to their background of studying English before entering the college
(three years, seven years and more than seven years) to serve the purpose of
the study: how to teach students of different levels to learn and practise
pronunciation of English stops effectively.
Thirdly, the subject was chosen in order to help the students overcome
the problems of stops pronunciation as soon as they begin their English
lessons at colleges.
Last but not least, the subject of the study would help provide some
necessary information about students’ background and attitudes towards
learning and practicing pronunciation in general and English stops in
particular, which contributes to the conducting of the survey of study.


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also the limitation of the study. The sample in this study is the response and
instances of students’ actual performance of English stops in sound
sequences.
3. 5. PROCEDURE
The study was carried out with the following steps:
1. Review the relevant documents, books and theses to set forth the
hypotheses basing on the preliminary contrastive information.
2. Deliver the questionnaires and collect the data to test the hypotheses
about the students’ situation of learning.
3. Implement the diagnostics tests from isolated words, sentences to
free talks that contain problematic sounds on production skill
(recording students’ actual performance) and on perceptive skill to
collect the data.
4. Analyze the data to get the evidence to test the hypotheses.
5. Discuss the result of findings.


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6. Suggest solutions to the problems to improve the matter of the
study.
3.6. METHOD OF DATA COLLECTION
The data of the study were obtained using 2 measurement instruments:
survey with questionnaires and diagnostic test.
The questionnaires were issued to the population of 100 students at Tuy
Hoa Industrial College. In order not to make the students get confused, the
researcher gave careful explanation of all the questions posed to the students.
Moreover, the students had as much time as they need to think over the
questions before they could make final decisions on the options or to show
their point of view to open-ended questions. (See Appendix A for the design

/p-b/

/t-d/

words

transcriptions

pin

/p n/

aspirated

bin

/b n/

partially devoiced

pen

/pen/

aspirated

Ben

/ben/


vowel shortening

pub

/p̚b/

vowel lengthening

Poppy

/p p /

vowel shortening

Bobby

/b b /

vowel lengthening

tore

/t :/

aspirated

door

/d :/


released

Requirements


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/k- /

ride

/ra d/

released

train

/tre n/

aspirated

drain

/dre n/

partially devoiced

trunk

/tr̚ k/


partially devoiced

curl

/k :l/

aspirated

girl

/

partially devoiced

class

/kl :s/

aspirated

glass

/ l :s/

partially devoiced

back

/b k/

Table 3.3 Requirements of the sentence test
Sentences

Requirements

1.

labialization of [t]

2.

labialization of [d]

3.

Audible release of [b]

4.

Linking [sl p n], labialization of [d]

5.

Linking and mutual assimilation; [k ld ju:] changes to [k ld u:]

6.

Devoicing [d]



interpreted with reference to a larger meaningful context” [17], therefore, the
students were asked to talk freely about one of the topics in the topic list in
order to test if they could perform English stops in connected speech or not.
In the scope of the study, all the recordings were then analyzed and
focussed on the mistakes of the stops only.
3.7. DATA COLLECTION
The data collection was executed on the subjects mentioned above. The
questionnaires were delivered to the students in May, 2007 after they had had
nearly ten months of getting accustomed to their learning environment at the
college. The diagnostic test was administered in June, 2007 on the ground of
the determined research design methodology.


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The collecting of the corpus was carried out in four stages:
Stage 1: The students were asked to pronounce the minimal pairs in the
word list after having 3 minutes to read through it;
Stage 2: The students were asked to read each sentence in the sentence
list after having 3 minutes to read through it;
Stage 3: Each of the students were asked to talk freely about a topic
they chose from the topic list after having 10 minutes to prepare and write
notes that was necessary for their talk;
Stage 4: The students were asked to listen to the tape and underline the
words they heard on the hand-outs delivered.
The diagnostic test was all recorded with the software “Polderbit Sound
Recorder and Sound Editor Version 4.0.0.90” and a microphone (Salar
Somic) connected to a laptop (hp). The recordings would make it possible for
the students’ performance to be transcribed, and then be collated with the
version produced by the English model tape as the baseline data. In addition,

other kinds of pronunciation mistakes, but we did not take such mistakes into
consideration. The mistakes were examined and totalled up to reinforce the
hypotheses. Accordingly, the students’ actual performance was judged with
qualitative and quantitative dimensions by recording, listening and comparing
carefully with the native speakers’ version. Along with this part, the
demonstration of the performance with the help of computer software like
“Speech Analyzer” and “Goldwave” were used to support our decisions on
students’ errors (as shown in Figure 3.1.a and Figure 3.1.b)


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Figure 3.1.a Audio signal of the word “pen”
performed by a student

Figure 3.1.b Audio signal of the word “pen”
performed by a native speaker
3.9. VALIDITY AND RELIABILITY
The data collection was carried out with 100 students taking part in the
questionnaires and 30 students in performing their pronunciation in terms of
perceptive and productive skill. These students were divided into three groups
to make the collation and verification more reliable. However, although the
students were selected in three groups of different levels and backgrounds,
they were required to do the same diagnostic test. They were treated equally
because they have to follow the same syllabus at the college without
mentioning their abilities. Also, we administered the research among the nonspecializing English students at Tuy Hoa Industrial College only, which
cannot be generalized to all the students at colleges. This is also the limitation


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