English has no rules for spelling or pronunciation, but there are some strong tendencies that may help us guess what is the most probable pronunciation of a word. I will tell you here the most important ones, but don't forget that you will find many exceptions to these rules, so don't try to memorize this list.

SYMBOL	Usual Spelling	EXAMPLES	less common	EXAMPLES
	ee / ea	seat, bean, cheek, sheep, teen	e (stressed)	be, these, complete
	i	sit, bin, chick, lip, tin	e (unstressed)	English, pretty, before
	e	set, neck, ten, fell, men	ea	bread, health, ready
	a	sat, ban, lack, pan, hat	-	-
	u	cut, bun, luck, much, cup	o	son, brother, love, month
	ar	cart, barn, cast, march, part	a	father, dance, bath
	o	cot, lock, posh, fox, cod	-	-
	or / au / aw	caught, port, forks, cord, born	-	-
	oo	book, took, good, look, foot	u	pull, put, butcher
	oo	fool, shook, soon, boom, mood	u	Luke, brute, flute
	stressed: er / ir / ur	bird, turn, perch, shirt, learn	wor	work, word, worse
	any vowel or vowel combination	Barbara, Photograph, a house, the sun, station	-	-
	a, ai/ay	station, face, Katy, day, May, stay, rain, paid	-	-
	i/y	fine, my, mine, pile, shine, pilot, five	-	-
	oi/oy	boy, boil, joy, toy, voice	-	-
	ou/ow	house, out, ground, how, town, allow	-	-
	o	phone, so, ago, home, alone, cold, both, post	ou/ow	soul, though, low, snow
	eer, ear	beer, cheer, steer, near, ear, dear, fear	-	-
	ear	chair, stair, fair, hair, fairy	-	-
	our/owr	hour, our, sour, flower, power	-	-
	ire	fire, admire, hire, tired	i+vowel	liar, science, giant