In English alphabet, there are five (5) Vowels- a, e, i, o and u. And there are two (2) more letters- y and w, which are called Semi-Vowels. In the word "cry", y is considered as Semi-vowel.
So, what is the use of "w" as Semi-vowel?
Learn English – the use of “w” as Semi-vowel
phonologysemivowelsvowels
Best Answer
TL;DR: When it is at the start of a syllable, not when it is at the end of a syllable.
First, do not confuse letters with sounds. It is pointless to talk about letters.
Semivowels are glides like /w/ and /j/ that act as part of a diphthong, so in conjunction with a vowel sound. In practice, only those semivowels that precede the vowel count as a consonant, not those that follow it where they count as a vowel.
So the words wet and yet are pronounced with a consonant glide at their fronts, and this is referred to as a semivowel because they start with a consonant sound. Contrast this with cow and coy where there is no consonant property involved, so those are purely vocalic: they end in a vowel sound, not in a consonant sound.
Spelling may or may not reflect this, though, because English spelling derives at best from the sounds of English that was spoken five to nine centuries ago, not from the sounds of English today. That’s why it’s pointless to talk about letters.
You have a false premise here: there is no semivowel in the word cry, only a purely vocalic, garden variety diphthong. The y in cry /kraɪ/ represents a falling diphthong /aɪ/, whereas the one is in yes /jɛs/ is the semi-vocalic glide /j/ you’re looking for, being the first element of a rising diphthong /jɛ/. Similarly in few /fju/.
Semi-vowels are things like /w/ and /j/, and they are frequently talked about only in rising diphthongs in English where they take on a consonant character. So cow has /kaʊ/ while coward has /ˈkaʊɚd/, which can also be written /ˈkawɚd/.
Similarly the noun toe and verb tow have /tou/, which can also be written /tow/. In concrete phonetics, you may see narrow transcriptions like [tʰo̞ʊ̯].
A semivowel at the start of the rising diphthong does not usually count as part of the syllable’s rime¹ so yet /jɛt/ rhymes with bet /bɛt/. Similarly the glide in queen /kwin/, [kʰwi:n] doesn’t count for rhyming, allowing it to rhyme with seen /sin/ and machine /məˈʃin/.
However with the /ju/ diphthong, some poets prefer to include the leading semivowel, preferring to rhyme cute /kjut/ with dispute /dɪˈspjut/ instead of with words lacking that /j/ component like shoot /ʃut/. So for them the vowel is the entire diphthong /ju/ including its leading semi-vowel and not just /u/, since they’re trying to rhyme with /jut/ not just with /ut/.