初中英语语法知识点之Be动词定义及用法讲解

Be动词定义及用法

1. Be动词有三个，am,is还有are.我用am, 你用are, is跟着他她它，复数全部都用are.

如果遇到过去时，was来把am,is替，were来把换掉动词are

2. do和be动词的用法区别

Be 动词就是(am，are,is)..句子中如果没有实意动词(例如:write，buy)之类的动词，就直接在主语后面加Be动词。而如果是句子中有实意动词，那么如果你要改为一般疑问句，就要借助DO(do也称为助动词)，例如:I study.

改为一般疑问句:Do you study ?

顺口溜：be氏三朵花, am, is还有are,

我(I)恋am, 你(you)恋are,

is跟了他(he)她(she)它(it),

单娶is, 复娶are。

详细讲解：

英语的be 动词是个用法比较复杂的动词。复杂的原因有两点：

1、 除了原形的 be 之外，对于不同人称代词以及单数名词和复数名词，be 会有各种变化形式和缩写形式。概括一下有七种形式：be, am, is, are, was, were, been, being。它们与人称代词和名词单、复数的搭配关系是：

现在时 I am, you are, he/she/it/ is, we/you/they are;名词单数、不可数名词用is，复数用are。

缩略式 I'm, you're, he's, we're, you're, they're

否定缩略式 I'm not, isn't, aren't

过去时 I was, you were, he/she/it/ was, we/you/they were;名词单数、不可数名词用was，复数用were。

否定缩略式 wasn't, weren't

过去分词 been

现在分词 being

2、在句子中，be有两种主要作用：一是作为系动词(The Linking Verb)，本身可以作用谓语动词;二是做为助动词(The Auxiliary Verb)，与谓语动词一起构成各种时态和被动语态等。

下面做个简要的讲解。

一、be 动词做系动词

1、系动词+表语”的结构

当be 动词做系动词使用时，主要构成“系动词+表语”的结构，在句子中做谓语。表语可以是名词、形容词、副词、介词短语等。例如：

The man is a science teacher.

Mary's new dresses are colourful.

Mother is in the kitchen now.

I have been there before.

They shall be here at 10:00 tommorow.

That can't be true.

You are not being very polite.

Your brother is being very annoying this evening

2、be 动词的一般疑问句，方法是把be 移到主语前面，也可说成是移到句首。

Is the man a science teacher? Yes, he is. / No, he isn't.

Are Mary's new dresses colourful? Yes, they are. / No, they aren't.

Was mother in the kitchen then? Yes, she was. / No, she wasn't.

Were you at home the day before yesterday? Yes, I was. / No, I wasn't.

Was she late this morning? Yes, she was. / No, she wasn't.