谈谈have作助动词用法

谈谈have作助动词用法
have在现代英语中是用得较多的动词之一。

它除了用作实义动词（ordinary verb）, 表示topssess （具有），to hold （保持），to experience （经验）等意义外,还大量用作助动词。

现就其助动词用法作一简述：
一、帮助构成完成时和完成进行时的各种时态。

例如：
1）完成时：
He has finished his task.
The sun had already set before we arrived at the railway station.
He shall have written the article by then.
2) 完成进行时：
I have been working as an interpreter for years.
He told me that he had been waiting for me even since the morning.
二、帮助构成复合谓语（和不定式动词连用）。

1) have to的用法。

具有语气动词的作用，表示必须履行的义务责任（obligation）, 或表示客观情况的需要，或必然性，几乎同情态动词must具有同样的意义。

例如：
I have to go there = I must go there.
If you want to catch the first train you have to leave at six.
He sees very badly, he has to wear glasses all the time.
The children have to play in the streets till their mothers get home from work.
In my district there is no gas laid on； people have to use electricity for every thing.
be to和have to在意义上是不相同的。

试比较下面两个句子：
We are to finish our work at five o'clock.
We have to finish our work at fine o'clock.
第一句are to finish 表示预定计划；这是大家知道的。

第二句“have to finish”表示“必须在什么时候完成”，不管我们愿不愿意。

2) had to的用法。

表示在过去时间里客观环境所产生的责任、任务或必然性，可用作
must的过去形式。

例如：
The buses were all full：I had to get a taxi.
She fell ill and had to leave early.
I got lost and had to ask a police man the way,
When I changed my job, I bad to move to another flat.
In October the expedition siled, but it had to make its way against adverse winds.
3)have to, had to常在会话中单独使用，这时不定式动词可不提及，但仍可理解。

例
如：
Do you have to translate the whole text into Japanese? No, you don't have to.
why do you always wear dark glasses?
I have to （wear them）. My eyes are very sensitive.
I didn't want to stop but I had to （stop） as I needed petral （汽油）。

三、have + object + past participle 结构.
1 ）可更为简洁地用来表示下列类型句子的说法。

例如：
I employed someonce to do something for me.
或：I employed a man to clean my house.
可说 I had my house cleaned,
使用这种结构时，一定要注意“have +Objetive + pp.”词序。

不然句子的意思就会改变。

试比较下面句子：
He had his hair cut.（请别人理了发）
He had cut his hair.（在说话前自己已理好发）。

这种结构的嶷问式和否定式要用do构成。

Do you have your windows cleaned every month?
I don't have them cleaned. I clean them my-self.
He was talking about having central heating put in. Did he have it put in in the end?
这种结构可用于进行时态。

例如：
I can't ask you to dinner this week as I am having my house painted at the moment and
everything is upside down.
He says that the house is too small and that he is having a room built on.
2) 这种结构在口语里可用来代替一个被动的动词，这个动词通常涉及某人的某种事故。

His fruit was stolen before he had a chance to pick it.可换为：
Fie had his fruit stolen before he had a chance to pick it.
Two of his teeth were knocked out in the fight.可以换为：He had two of his teeth knocked out in the fight.
在上述1）组里，可以看到句子的主语通常为命令某人做某事的人，但在2 ）组里，句子的主语则是遭受某种行为结果的人。

在这组里主语还可以是物、东西。

例如：The houses had their roofs ripped off by the gale.
73
四、 have + object + present participle 结构.
1 )第一种用法表示作为某人努力的一种结果。

例如：
I will have you driving in three days. (As a result of my efforts)you will be driving in three days.
这种形式常用于上述将来一段时间，也可用于现在时和过去时。

例如：
He had them all dancing = He taught persuded them all to dance.
I have them all talking to each others I encouraged/persuade them all to talk to each other.
这种形式也可用于疑问句中，但通常不用于否定句。

Will you really have her driving in three days?
2) 第二种用法表示句子主语将遇到或可能遇到某种不愉快的事。

例如：
If you give all-night parties you'll have the neighbours complaining, (the neighbours will complain/will be complaining).
If film-stars put their numbers in Telephone books they would have everyone ringing them up.
五、 had better + infinifive 不带 to的用法。

这是一种很有用的劝告或警吿某人做某事的形式。

had在这里并不是真实的过去，而是指现在或将来。

如：
You had/you'd better start tomorrow.
I had/I'd better ring him at once.
You'd better return this book today.
He had better mend the fuse
否定形式是把not放在better之后组成。

例如：
You had better not miss the last bus.
(I advise you not to miss it.)
Then you'd better not answer his letter now.
had better通常不正式用在一般疑问句中，但有时可用于疑问句(作为一种劝吿形式) 例如：
Hadn't you better ask him first?
Hadn't you better renew her licence?
Hadn't you better enroll first?
注意下列用法：
I had better go by train = It would be best for me to go by train. You had better go by bus - It would be best for you to go by bus. 在间接引语中had better和第一或第三人称连用时保持不变，和第二人称连用也可不变，或用：
advise + object + infinitive 来表示：
He said, "Mary had better hurry气
He said that Mary had better hurry,。