Why is y a vowel?

Answer 1

Vowels are A, E, I, O, U, and sometimes Y.

Y is a vowel in the words rhythm, system, syllable, mystery, and cyst. Here it takes the place of the vowels E and I. In the word "boy" it creates a diphthong (oi), so it is a vowel. Y is considered a consonant only when it appears at the start of a syllable where there is another vowel (yam, yet).

In the word player, the "yuh" sound is heard, so Y is a consonant. Less clear are the words "day" and "obey" where the "silent Y" may be considered either a consonant or a vowel.