Interlanguage Phonology of Korean Learners of English

Korean and English Stops

Phoneme Substitutions

Syllable Structure

Vowel Insertion

Stop Voicing

Nasalization

/n/-Insertion

conclusion


1. Korean and English Stops

    While Korean has three distinctive voiceless stops as phonemes, English has two distinctive stops: voiceless stops /p, t, k/ and voiced stops /b, d, g/. Voiceless stops are aspirated in the word initial or in the stressed-syllable initial position, but they are not aspirated after /s/ and in the unstressed-syllable initial position, and they remain unexploded in the syllable coda position. The following show the Korean and English stop phonemes and allophones. The most similar sounds are linked together. [Note: English unaspirated voiceless stops sound more similar to Korean fortis stops rather than lenis stops. ]
    (1) Korean and English Stop Phonemes and Allophones

2. Phoneme Substitutions

    Koreans tend to substitute Korean /p, t, k/ for English /p, t, k/, and Korean /p, t, k/ for English /b, d, g/, which causes a devoicing problem in the word initial or word final position. [Note: Actually, the result of Major & Faudree (1996) shows that the voiced stops in the word initial position are not a big problem to Korean learners of English. They conclude that the subjects overcame the difficulty of voicing in the word initial position. However, according to Ladefoged (1993), native listeners of English differentiate a voiceless stop and a voiced stop in the word initial position by the presence of aspiration not by the presence of voicing, and also those in the word final position by the duration of preceding vowels not by the presence of voicing, since English stops in those positions are partially devoiced. Thus, the Korean speakers do not seem to have problems in differentiating voiceless stops (= aspirated ones) and voiced stops (= unaspirated lenis ones) in the word initial position. However, many Korean learners of English do not know that the vowel duration is longer before a voiced consonant than before a corresponding voiceless consonant. This must have lead to much poorer result in the production of word final voiced stops in Major & Faudree's (1996) experiment. ] The following are consonant substitutions (H-B Park, 1992:59) and vowel substitutions made by Korean speakers:

    (2) a. Consonat Substitutions

    b. Vowel Substitutions

3. Syllable Structure

    Not only the phoneme inventories but also the syllable structures of English and Korean are quite different from each other. The Korean syllable structure is much simpler than that of English: V, CV or CVC. It does not allow consonant clusters, [Note: There is some debate about the treatment of glide in the Korean syllable structure. It has usually been regarded as part of a vowel (C-W Kim & H-Y Kim, 1991) owing to the orthography, but recently there is another claim that it may not part of a vowel but an onset element (YS Lee, 1983). If such a claim is admitted, we may say Korean allows a consonant cluster only in the form of "C + G" in the syllable onset position. However, because this issue is beyond the scope of the present study, it will not be considered further here.] and the syllable coda position is restricted to only lenis stops /p, t, k/, nasals /m, n, / and a lateral /l/.


4. Vowel Insertion

    Broselow (1987:272) proposes the following Syllable Structure Transfer Hypothesis:

    (3) Syllable Structure Transfer Hypothesis
    When the target language permits syllable structures which are not permitted in the native language, learners will make errors which involve altering these structures to those which would be permitted in the native language.

    Korean speakers learning English seem to support this hypothesis. Inserting a vowel, they try to break consonant clusters. They also insert a vowel after a fricative or an affricate sound, since fricatives or affricates in the syllable coda position, without vowel insertion, would be neutralized as /t/ under the application of SFNR (1). That is, bus might be homophonous with but. Due to the epenthesis, the original syllable-final fricative or affricate is resyllabified as a syllable-initial one, and can be realized as a more similar sound to the target language (Nam & Southard, 1994:267). A high front vowel /i/ is inserted after a palatal sound such as /, , , / and a high back unrounded vowel // is inserted elsewhere (Ahn, 1991:15; Tak, 1996:768, 775). The following are some examples of vowel insertion by Korean speakers:

    (4)   a. Christmas    -->   [krismas]
          b. church       -->   [:i]
    In (4b), /r/ in the coda position is deleted, since Korean syllable system does not allow /r/ in this position, and instead its preceding vowel is compensatorily lengthened. [This is by chance similar to British English. However, usually, Korean speakers are not taught British English pronunciation at school. If /r/ is not deleted, it may be neutralized as /l/ by Korean speakers, which must lead to a more undesirable result.]
    On the other hand, H-B Park (1992) insists that Korean speakers insert // after a stop, if its preceding vowel is a tense/long vowel or a diphthong, giving the following examples:
    (5)  a. [pi:k]       'peak'
            [kout]       'coat'
            [paip]       'pipe'
         b. [pik]          'pick'
            [kut]           'good'
            [tip]          'tip'
    However, as shown in the variants [keik] and [keik] for cake, or in the variants [taip] and [taip] for type, vowel insertion may not apply even after a diphthong. K-J Lee (1992) has the similar idea to H-B Park (1992). Exemplifying that dog has two different variants [tok] and [to:g] but guide or league are always realized as [kaid] and [li:g], she insists that an English syllable-final voiced stop is epenthesized when following a long vowel or a diphthong, and that it is unreleased when following a short vowel. In fact, a syllable-final voiced stop tends to be epenthesized quite easily, even if it is preceded by a short/lax vowel as shown in [kg] for gag. This is because the devoiced stop sound by substituting Korean /k/ for English /g/ can be voiced again by Lenis Stop Voicing Rule through vowel insertion. It would be interesting to investigate which strategy (devoicing but keeping the syllable structure, or preserving voicing but adding a syllable through vowel insertion) Korean speakers use more often in such a situation and which is better on the viewpoint of intelligibility by native speakers of English. To sum up, the vowel insertion rules can be formulated as follows:

    (6) Vowel Insertion Rules

    a. In the case of a consonant cluster in the syllable onset position

    b. In the case of a consonant cluster in the syllable coda position

    b-1 If the first consonant following the vowel is permissible in the coda position

    b-2 If the first consonant following the vowel is not permissible

    c. In the case of a consonant in the syllable coda position

    c-1. If a non-sonorant consonant is preceded by a long vowel or a diphthong

    c-2. If the consonant is not permissible in the syllable coda position


5. Transfer of LSVR (Lenis Stop Voicing Rule)

    The transfer of LSVR results in voicing a voiceless stop in an intervocalic position. Not a few Korean learners of English tend to mispronounce stop it as [stabit], or check up as [egp]. Their derivations can be displayed as follows:
    (7)

    [Exmple of waveform, spectrogram or actual sound]


6. Transfer of Nasalization (NasR)

    The transfer of NasR seems to be more serious. Many Koreans pronounce pop music as [pam mjuik], and nickname as [ni neim] (Nam & Southard, 1994).

    [Exmple of waveform, spectrogram or actual sound]


7. Transfer of /n/-Insertion Rule

    A pronunciation of Look at yourself can be described as follows:
    (8)

    [Exmple of waveform, spectrogram or actual sound]


8. Conclusion

    In conclusion, Korean learners of English tend to transfer Korean phonological rules such as SFNR, LSVR, NasR, etc. to English. They also use vowel insertion to admit permissible syllable structures. The degree of transfer consistency of these rules may be different from each other. That is, those who transfer LSVR also seem to transfer NasR, but those who do not transfer NasR do not seem to transfer LSVR. In order to elucidate such a postulation, more empirical research is required. Such a difference would be a good tool for judging the development degree of an L2 learner's acquisition of L2 phonology or the degree of his or her fossilization in L2 pronunciation.


    [last updated June 25, 1999]
    Hyouk-Keun Kim