In English spelling, Y can be a vowel or a semivowel (you can look up semivowel online — the wikipedia will tell you more than you need to know), depending on the word. Here are some very quick thoughts: Y as a vowel: myth, study Y as a consonant (actually a semivowel / semi-consonant): you, beyond (also, the U can begin in this sound: use) Y as an off glide (a semivowel, but usually analyzed as a vowel in English and Portuguese): pay Y as a vowel followed by a glide: scythe, analyze Covering the subject would take a book at least, but if you tell me why you want to know (are you concerned with spelling, pronunciation, trivia?) I’ll be happy to fill you in.

The letter 'y' is a consonant in English spelling. It sometimes represents a vowel sound ( as in the word 'sky', for example), but it is not a vowel itself. In English, we have five vowels just as you do in Portuguese: A E I O U.