Hiatus is the opposite of diphthong.
In the English language there are 3 different hiatus.
Hiatus is usually composed like it follows: vowel + pause + vowel + consonant.
Below you can read the phonetic transcription of hiatus:
Hiatus are words that contain two vowels, they are not pronounced together as one sound, but each vowel is pronounced separately. To make the separation we make a small pause as there is no consonant in between them.