实义动词包括及物动词，不及物动词和连系动词---连系动词介于及物和不及物动词之间。请点击及物和不及物动词，系表结构了解详情。

当我们提起助动词，它的功能顾名思义就是帮助实义动词---帮助实义动词改变时态，单复数，说话者的意思（变成否定句和疑问句）。助动词主要有：do(does, did), be(am, is, are, was, were), have(has, had), shall (should), will (would).

1） 改变时态
He always gets up at 6am.
He will get up at 6am.
He would get up at 6am.
He is getting up now.
He was getting up.
He has already got up.
He had already got up.

2） 改变单复数
I am getting up now
You are getting up now.
He is getting up now.
They are getting up now.

I have done this job.
You have done this job.
He has done this job.

I was wrong.
You were wrong.
She was wrong.
They were wrong.

3） 肯定变否定
He always plays football.
He doesn’t always play football.

He played football yesterday.
He didn’t play football yesterday.

He is working now.
He is not working now.

He has finished this job.
He has not finished this job.

He will do this job.
He will not do this job.

4） 提问
He always plays football.
Does he always play football?

He played football yesterday.
Did he play football yesterday?

He is working now.
Is he working now?

He has finished this job.
Has he finished this job?

He will do this job.
Will he do this job?

情态动词表示说话人的感情，需要，态度等。情态动词的最大特点是后面必须加动词原形。
主要的情态动词有：can (只有过去时could), be able to（有各种时态）, may (只有过去时might), must, should, ought to

1 He can repair computers.

2 She told me that he could repair computers.

3 He could run very fast 10 years ago.

1 You can go home now.

2 You can use my computer, but you have to return it back to me tomorrow.

1 He can be right.

2 They can be twins.

1 Could I give you a hand to lift this heavy box upstairs?

2 Could you be very kind to give me a hand please?

3 Could you please turn down the radio a little bit?

1 He is able to repair computers.

2 He will be able to go home in two moths.

3 He has been able to speak fluent English for two years.

4 He told me that he had been able to drive a truck for two years.

1 You may use my computer.

2 May I smoke in this room?

3 He told me that I might smoke in this room.

4 He told me that I might use his computer for two days.

1 Might I smoke here?

2 Might I use your computer?

You must go there.
You must not go there.
Must I go there?

You should go there.
You should not go there.
Should I go there?

You ought to go there.
You ought not (to) go there.
Ought I(to) go there?

1 I have to finish my homework now./ He has to finish his homework now.

2 I do not have to finish my homework now./ He does not have to finish his homework now.

3 Do I have to finish my homework now?/ Does he have to finish his homework now?

4 I had to finish my homework yesterday./ He had to finish his homework yesterday.

5 I will have to finish my homework tomorrow./ He will have to finish his homework tomorrow.

比较 may 和 must

May 和must 都表示猜测和可能性。May暗含不确定，Must暗含很可能。

1） 对现在发生的事情的猜测

　　He may be right now.
　　他现在可能是对的。

　　He must be right now.
　　他现在一定是对的。

2） 对过去发生的事情的猜测

　　He may have done that math question before.
　　他以前可能做过那道数学题。

　　He must have done that math question before.
　　他以前肯定做过那道数学题。

特别注意

第一个句子表示应该干的事而没干，第二个句子表示不应该干的事而干了.

　1) You should have finished this job.
　　　你早应该做完这份工作了。

　2) You should not have lied.
　　　你不应该撒谎。

词组动词就是动词加介词或者副词构成的固定词组。它的功能相当于一个普通动词。

Take off Put down Get over Think over

动词+副词

Look for Look after Listen to Care for

动词+介词

１　The plane will take off at 9am.

２　Please put down your hat on the table.

３　He is looking for his pen.

４　They are listening to the teacher carefully.