并列关系

He can sing and he can dance.
He can sing and dance.
He can both sing and dance.(both…and…两者都)
He can not only sing but also dance.(不但..而且)

选择关系

You may go or stay.(或者)
Hurry up or you’ll be late for school.(不然)
Either Tom or Jerry must sing a song.(eithor..or…或者…或者(二选一))
Neither Tom nor Jerry must sing a song.(neithor..nor…两者都不(二全否))

转折关系

Many is a pretty girl, but i don’t like her.(但是,然而)
Many is a pretty girl, yet he doesn’t like her.(但是,然而(惊讶))
Many is a pretty girl. However, i don’t like her.(但是,然而(没有连接作用,起转折副词))