In linguistics, an epenthetic vowel breaks up a consonant cluster that is not permitted by the phonotactics of a language. Vowel epenthesis typically occurs when words are borrowed from a language that has consonant clusters or syllable coda consonants that are not permitted in the borrowing language, but this is not always the cause. Various languages use different vowels for this purpose.

• Hebrew and English use a single vowel, the schwa.
• Japanese uses [u] except following [t] and [d], when it uses [o]. For example, the English word street is /sutorito/ in Japanese.
• Korean uses "ㅡ" /ɨ/.
• Colloquial Brazilian Portuguese uses [i] in such words as psicologia, pronounced /pissicologia/. One finds the same pattern in certain variants of Southern American English, e.g. nuclear, pronounced /nukiljar/. This common phonological trait can possibly be retraced to a common origin in the West-African languages brought by slavery.
• In standard Finnish, foreign words never cause epenthesis, and any kind of epenthesis is actually absent. However, some dialects like Savo and Ostrobothnian use an epenthetic vowel. There is no schwa in Finnish, although this term is sometimes used for the epenthetic vowel, whatever it is. The epenthetic vowel is the preceding vowel, appearing in -lC- and -hC-, and in Savo, -nh-, e.g. Pohjanmaa "Ostrobothnia" → Pohojammaa, ryhmä → ryhymä. In Finnish, any consonant clusters occur only between syllables, e.g. kol-mas, where the L, H or N are slightly intensified to achieve a distinctive sound. In the concerned dialects, the consonants gain an epenthetic vowel instead. Ambiguities may result: Salmi (a name) vs. salami. However, in Pohjanmaa, -lj- and -rj- become -lij- and -rij-, respectively. (Foreign words do not cause epenthesis, but words ending in consonants gain -i when they are nativized or a case ending is added, e.g. tank → tankki and thus e.g. translative tankiksi. This has little to do with phonotactics: it is standard grammar, as e.g. moottorvene "motorboat" is perfectly pronounceable to a Finnish speaker and even the standard form in the Savo dialect.)

Reference

Välivokaali