The plural of 'el rey'

The plural of 'el rey'
 

¡Buenas!

When a spanish word ends in a vowel , we make it plural by adding only S.

Example ( Un libro : Los libros )


But , (Un rey) becomes ( Los Reyes ) in the plural !

Is it because Y is not a vowel in spanish ? did I get that right ?

¡muchas gracias!

The letter 'y', when it ends a word, is known as a semivowel.

There's a rule that says 'es' is added to nouns that end in 'y'.
(But the rule doesn't apply to 'loan words', like 'jersey' or 'gay'.)

(There are other rules regarding nouns that end in accented vowels, by the way.)

Thanks for clearing that up.