用diphthong造句子，“diphthong”造句

the syllabic `l' in `riddle' or the syllabic `n' in `botany' when pronounced `bot-n-y'; (of a vowel sound) dominating the other vowel sounds in a syllable as being the first vowel in a falling diphthong; the syllabic `o' in `oi'.

the contraction of two vowels into a diphthong.