English questions whats a vowel

a, e, i, o, u

Explanation:

a speech sound which is produced by comparatively open configuration of the vocal tract, with vibration of the vocal cords but without audible friction, and which is a unit of the sound system of a language that forms the nucleus of a syllable.

a vowel is what makes a word a word, it is the letters a, e, i, o, u

Explanation: A word cannot be a word if it wasn't for vowels because they are what makes the word be able to be pronounced.