I am an expert on writing systems.
I can tell u that English has 43 speech sounds, as listed and shown in the words below:
/a/ (ant), /ai/ (rain), /ar/ (arm), /air/ (air), /au/ (autumn),
/b/ (bed), /ch/ (chip), /d/ (dog),
/e/ (egg), /ee/ (eel), /er/ (herb),
/f/ (fish), /g/ (garden), /h/ (house),
/i/ (ink), /igh (high), /j/ (jug), /k/ (kite),
/l/ (lips), /m/ (man), /n/ (nose), /ng/ (ring),
/o/ (on), /oe/ (toe), /oi/ (coin),
long /oo/ (food), short /oo/ (wood), /or/ (order), /ou/ (out),
/p/ (pin), /r/ (rug), /s/ (sun), /sh/ (shop),
/t/ (tap), /th/ (this), /th/ (thing),
/u/ (cup), /ue/ (cue), /v/ (van), /w/ (window), /y/ (yak), /z/ (zip), /si/ (television)
It also has an unstressed half-vowel
which linguists call ?schwa?
which occurs mainly in endings and is often spelt , as in ?flatten, flatter, artery, decide? (but not in abandon, certain....)
Children need to be made aware that words are made up of sounds, but for reading, they mainly have to learn the sounds for the graphemes used for them, the main 90 of which I listed above.
I have often asked people who claim to be phonics experts to explain on here exactly how they teach the variant pronunciations of graphemes, but they never do. Perhaps u will?