(1)have作“有”讲,强调“所属关系”,含有“拥有”之意。其主语一般是人,有时也可以是物。
They have many new books. 他们有许多新书。
Wei Hua has a little brother. 魏华有个小弟弟。
This table has four legs. 这张桌子有四条腿。
(2)have可以作“买”讲。
I want to have a kilo of beef. 我想买一公斤牛肉。
May I have a new pen? 我可以买支新笔吗?
(3)have作“用、使用”讲
Excuse me, may I have your bike, please? 打扰了,我可以用(借用)你的自行车吗?
had则是have的过去式