汉语中只有助词,而没有助动词。这又是英汉两种语言的一大差别。英语的助动词,就是起辅助作用的动词,本身没有独立的词义,不能单独做谓语,在句子中只起语法作用,和实意动词一起构成谓语(叫复合谓语),表达否定,疑问,时态,语态和其他语法关系。其基本形式和作用如下表:

原形 现在式 过去式 过去分词 现在分词 作用
Be Am, is, are Was, were Been Being 构成各种进行时态和被动语态
Have Has, have Had —— —— 构成各种完成时态
do Does, do Did —— —— 构成疑问句和否定句,加强语气,代替前面相同的动词
Shall —— Should —— —— 构成各种将来时态
Will —— would —— —— 构成各种将来时态

(一)助动词be的用法

1、跟现在分词构成各种进行时态:

They are playing war games with toy guns and toy tanks. 他们正在用玩具枪和玩具坦克玩战争游戏。 

We were playing video games on TV last night. 昨晚我们在电视上玩电子游戏。 

2、跟过去分词构成被动语态: 

He’s not respected by the press. 他们不受报界的尊重。 

We were taught how to use a computer last year. 去年教过我们怎样用计算机。 

(二)助动词have的用法 

have后面跟过去分词构成各种完成时态: 

We’ve known each other since three years ago. 我们从三年前就认识了。 

He’s been to Shanghai. 他去过上海。 

(三)助动词do的用法 

1、帮助构成实意动词一般现在时和一般过去时的疑问式和否定式: 

Do you know John? 你认识约翰吗? 

Mary didn’t come to see me yesterday. 玛丽昨天没来看我。 

You like this picture, don’t you? 你喜欢这张画,不是吗? 

2、代替前面已经提到过的动词,避免重复: 

Do you smoke? ?Yes, I do. 你抽烟吗?-是的,我抽。 

I smoke. So does he. 我抽烟。他也抽。 

He doesn’t like it. Neither do I. 他不喜欢,我也不。 

They went swimming yesterday. So did we. 他们昨天去游泳了。我们也去了。 

3、帮助加强谓语动词的语气: 

I do like you. 我真的喜欢你。 

She/He does like you. 她/他确实喜欢你。 

She/They/We did go swimming yesterday. 她/他们/我们昨天确实去游泳了。 

If you do know, answer me in a loud voice so that all may hear. 如果你的确知道,就大声回答我,以便大家都能听见。 

be, have, do 都能做实意动词用: 

These are computers. 这些是计算机。 

We’re having breakfast. 我们正在吃早饭。 

I did some washing last night. 我昨晚洗了衣服。 

(四)助动词shall和will的用法 

1、助动词shall/will构成一般将来时;should/would构成过去将来时 

We shall/will be rich, if we succeed. 我们将很富有,如果我们成功的话。 

They will be rich, if they succeed. 他们将很富有,如果他们成功的话。 

They said they would be rich, if they succeeded. 他们说他们将很富有,如果他们成功的话。 

2、shall 用在第一、三人称作主语的疑问句中,来征求意见,表示“要不要……” 

Shall I go now? 要我现在就走吗? 

Shall we invite her, too? 我们也邀请她吗? 

Shall the house be insured against fire? 要给房子保火险吗? 

Shall the reporters wait outside or what? 要记者们在外面等还是怎样? 

3、shall 用于所有人称,表示说话人的决心、保证、许诺、威胁、警告、命令等强烈的感情。例如: 

You shall have an answer by tomorrow. 到了明天,你会得到答复的。 

If he’s good, he shall have a new watch for Christmas. 如果他表现好,在圣诞节就会得到一块新表。 

You shall suffer for this. 你会为这事吃苦头/付出代价的! 

I don’t want to be hard on them; they shan’t be pressed. 我不想难为他们;不会过于逼迫他们的。 

They hope to undermine our unity; they shall fail. 他们希望破坏我们的团结:他们不会成功的。 

If you children don’t do as I tell you, you shan’t go to the party. 你们小孩要是不听话,就不让你们参加晚会。 

As a man sows, so he shall reap. 善有善报,恶有恶报。(谚语) 

Then you shall come; and you will come too, Ruth, won’t you? 那你得来;Ruth,你也来好吗? 

4、would 可以表示过去的习惯,类似used to: 

He would come to see me on Sunday when he was here. 他在这里的时候,星期天就来看我。 

The dog would lie there in the sun all afternoon. 那只狗常常整个下午躺在那里的太阳底下。 

When we were children, we would go skating every winter. 小的时候,每年冬天我们都去滑冰。 

5、will可以表示“愿意、肯、会、固执”等意义,而非将来: 

I meant to reason with you, but you won’t reason. 我打算和你讲理,但是你就是不讲理。 

I will pay you for it. 我会付给你钱买下它的。 

Go where you will. 到你愿意去的地方。 

She won’t so much as look at David. 她连看都不看一眼大卫。 

We’re going on a climbing trip. Come if you will. 我们要去爬山。你愿意的话就跟我们一起来。 

6、will可以表示倾向、习惯(总是会,老是等意思),在否定句中可以表示“不肯、不能”等意思: 

Boys will be boys. 男孩子总归是男孩子。 

A wise man changes his mind; a fool never will. 聪明人会改变自己的思想,而傻子却不会。 

Sometimes the cat will lie there all morning. 有时候猫会整个下午躺在那里。 

Oil and water will not mix. 油和水是不会混合在一起的。 

She will sit there for hours, waiting for her son to come back. 她总是在那里坐上好几个小时,等她儿子回来。 

This machine won’t work. 这台机器不工作了/坏了。 

These things will happen. 这样的事情总是会发生的