The purpose of this paper is to investigate the distributions and acoustic characteristics of /ɨi/ found in Seoul Corpus. The monophthongization of /ɨi/ occurs in 93.04% of a total of 2,370 tokens and in higher than 99% of the cases with onsets and of non-initial position in a word. However, only 31.82% of word-initial tokens are monophthongized. 94.40% of monoph- thongized /ɨi/ tokens are realized as [i], but in word-initial position, 61.74% of the monophthongized diphthong tokens are realized as [ɨ]. Based on acoustic properties, /ɨi/ in Korean is not off-glide [ɨj] but on-glide [ɰi]. The 165 diphthongs which are realized [ɰi] are classified under two patterns. The first type (97 tokens) is composed of on-glide and vowel. The second type (68 tokens) is composed of only on-glide transition. Acoustically the first type is longer than the second type in duration. Also, the first type begins with a more front position than the second type and moves to a position that is more back than the second type.

The purpose of this study is to investigate pronunciation deviations of German diphthongs for Korean learners residing in Daegu and Gyeongbuk regions. When Korean learners utter German diphthongs such as /a͜i/, /a͜u/ and /ɔ͜y/, this study is to analyze what phonetic features appear to be realized in segmental and suprasegmental perspectives and find out the reasons to eventually contribute to reducing Korean learners’ pronunciation deviations of German diphthongs. The results of the experiment are as follows. First, when Korean learners utter German diphthongs, they were realized mostly in two syllables. Second, as to the descent degree of intensity in a suprasegmental perspective, the difference in a case of intensity realization of /a͜i/ between Korean learners and Germen speakers was shown to be the biggest. Third, in terms of length (utterance duration), the biggest difference with German speakers was shown to be found when Korean learners uttering /a͜u/. Fourth, in a segmental perspective, the pronunciation deviation of /ɔ͜y/ was found to be the biggest. The reasons that these pronunciation deviations appeared may include the negative transference phenomenon of mother tongue that worked on deviations the most, and other correlations with lack of awareness of phonetic rules about the relations of German grapheme‐phoneme rules, phonetic features of German diphthongs,—for instance, features including a single syllable utterance, and/or the feature of intensity descent of syllables when consecutively connected to non‐syllables.