The letter Y has more than one sound.
Y at the beginning of a word is a consonant.
Y anywhere else in a word is a vowel. If y is the only working (sounded) vowel in a single syllable word, it will behave like i.
Y as short i (words that follow Phonetic Skills 1 and 2): When y is followed by one or two consonants, the vowel sound is short i.
Y as long i (words that follow Phonetic Skills 3 and 4): When y is alone at the end of a single-syllable word, the sound is long i. When y is the only working vowel in a word ending in silent e, they y will be long i.
Y as an adjacent vowel (words that follow Phonetic Skill 5): When y is an adjacent vowel, it is silent (exceptions: they, grey, prey, and whey).
Y in rainbow s and rainbow s words: When y is next to c or g in a word, it creates the same sound as i in ci and gi (examples: cyst and gym).