Countries but all Vowels are Changed to O

Consonants and vowels are types of phones that we use in the English language

Letters may carry these phones in speech, for example X can make the sounds /z/, /ks/, or /gz/

Letters aren't consonants or vowels by themselves but they will frequently be classified as such

Now back to consonants. A consonant is linguistically defined as a phone where the vocal tract is partially or completely constricted, aside from the glottal /h/

Also normally included in consonants are the liquids/glides, including /j/ (palatal glide)

So, Y can take on different phonemes in English, such as yellow - /j/, sky - /aɪ/, happy - /i/, gym - /ɪ/

I know we definitely agree that the letter I isn't a consonant. So if I is a vowel, and Y makes these sounds which I makes, then why is Y a consonant??

Point is, English phonology/phonetics is not a black-and-white thing, most definitions are fuzzy

also, maybe this is just a lack of linguistic education but you can easily tell if Y is functioning as a semivowel (glide) or a vowel if there's constriction in the vocal tract, in this case it makes the /i/ vowel (FLEECE), so unless you consider «fleece» to be vowel-less then maybe it's best not to think of letters as «consonants» or «vowels», and more of the sounds letters may carry as such :D