ウェブIn the International Phonetic Alphabet, an inverted breve below is used to mark a vowel as non-syllabic, i.e. assuming the role of a semivowel. The diacritic thus expands upon the four primary symbols [j, w, ɥ, ɰ] the IPA reserves for semivowels, which correspond to the full vowels [i, u, y, ɯ], respectively.