Diphthongs contrast with monophthongs, where the tongue or other speech organs do not move and the syllable contains only a single vowel sound. For instance, in English, the word ah is spoken as a monophthong (), while the word ow is spoken as a diphthong in most varieties (). Where two adjacent vowel sounds occur in different syllables (e.g. in the English word re-elect) the result is described as hiatus, not as a diphthong.
Diphthongs contrast with monophthongs, where the ton,gue or other speech organs do not move and the syllable con?tains only a single vowel sound. For instance, in English, the word ah is spoken as a monophthong (), while the word ow is spoken as a diphthong in most varieties (). Where two adjacent vowel sounds occur in different syllables (e.g. in the English word re-elect) the result is described as hiatus, not as a diphthong.