Hiatus are the opposite of diphthongs: words containing two consecutive vowels that are pronounced in two different syllables. There are three different hiatus in English.
Hiatus are usually composed with the structure: consonant + vowel + pause + vowel + consonant.
The pause is used to represent that the vowels belong to different syllables.
The three hiatus in English are:
Hiatus are used to define the pronunciation of a word.
External link to Hiatus exercises (1207).