One definition is the letters ‘a’, ‘e’, ‘i’, ‘o’, and ‘u’ (and sometimes ‘y’). The other is the speech sound without any blockage or constricting of the vocal tract. Vowel letters are used in written English to indicate vowel sounds, but because English is a pain in the ass, there’s no 1 to 1 match between the 5(ish) vowel letters and the 20+ vowel sounds.
Vowel has 2 definitions that conflict.
One definition is the letters ‘a’, ‘e’, ‘i’, ‘o’, and ‘u’ (and sometimes ‘y’). The other is the speech sound without any blockage or constricting of the vocal tract. Vowel letters are used in written English to indicate vowel sounds, but because English is a pain in the ass, there’s no 1 to 1 match between the 5(ish) vowel letters and the 20+ vowel sounds.