第1个回答 2013-12-03
主语为第一二人称用have例如 l have a big room 例如you have trouble主语为第三人称用has例如he has a girlfriend过去时用had 例如l had a big dinner yesterday
第2个回答 2013-12-04
通常与介词to 形成短语,have to=must是不得不;必须的意思,相当于一个情态动词,后面加动词原形,构成短语have to do sth.如:I have an apple.我有一个苹果。这的意思是“有”。I have to do my homework.我不得不做我的家庭作业。是必须的意思
have表示”使“时(即用做使役动词)的用法有三种:
1.have sb/sth do sth:表示使某人做某事。
例:The teacher has students do homework every day.
2.have sb/sth doing sth:表示使某人一直做某事
例:He has the horse running all day.
3.have sb/sth done:表示使某人被...
例:He has his hair cut by his father.
单数时,须把have改为has.
第3个回答 2013-12-03
have是原形,has是第三人称单数,had是have的过去式与过去式分词。