u的发音就2种，[ʌ]和[ju:]。
发音[ʌ] ：but、nut、jump、buff、butterfly、mud
发音[ju:]：few、cute、use、useful、used、usual、university、usually、unique
常发/ u:/的字母/字母组合：oo, ou, o, u
oo - food, too, mood, loose, school, tool, pool
ou - soup, route, group
o - who, do, move, lose
u – super
不常见/ u:/的字母组合：oe, ui, ue
oe, ui, ue - shoe, juice, continue
现代英音/ʊ/的发音：更加靠近/ə/，可以在/ə/的发音基础之上，嘴唇稍微聚拢，依然保持“呃”的声音。
常发/ʊ/的字母/字母组合：oo, u, oul
oo - good, foot, cook, book, look
u - put, full, pull, push
oul - should, would, could
