單詞的積累和語法的掌握是學(xué)習(xí)英語的重中之重，下面是小編給大家分享的常用英語語法知識，大家可以作為學(xué)習(xí)的參考。

1、系動詞+表語”的結(jié)構(gòu)

當(dāng)be 動詞做系動詞使用時，主要構(gòu)成“系動詞+表語”的結(jié)構(gòu)，在句子中做謂語。表語可以是名詞、形容詞、副詞、介詞短語等。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 動詞的一般疑問句，方法是把be 移到主語前面，也可說成是移到句首。

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.

3、be 動詞用在特殊疑問句

在特殊疑問句里，be 動詞仍然移到主語前面，但特殊疑問句是以特殊疑問詞開頭的，所以be 動詞只能說是移到主語前面，或者說是在特殊疑問詞的后面。例如：

Whose bike is broken? Xiao Ming's bike is.

Who was singing in the room? Mr. Zhang was.

Where are you from? I am from Wuhu.

What class were you in? We were in Class 2.

How old is Tom? He is ten.

4、be 動詞的否定句

be 動詞做謂語時，它的否定形式是在be 后加not，并且可以縮寫。例如：

It is not sunny today.

Tom and his friends are not in the park.

You were not nine years old when I went to the university.

He was not often late for his class when he was a student.

I wasn't here yesterday.

My parents weren't at home last Sunday.

5、be 動詞的祈使句

be 動詞的祈使句有肯定和否定兩種形式?？隙ㄐ问绞且詁e 動詞開頭，而否定形式或強調(diào)句形，要加don't 或do。例如：

Be careful!

Be a good boy!

Don't be silly!

Don't be a fool!

Do be obedient!

Do be careful.

英語中be動詞的用法：

作為系動詞(也叫連系動詞，link verb)的be，是英語學(xué)習(xí)者接觸最早的用法，而且其用法也很多。其基本含義為“是”，基本用法結(jié)構(gòu)為“主語+be+表語”，也就是我們常說的主系表結(jié)構(gòu)，其中的表語一般都由名詞、形容詞、數(shù)詞或表地點、時間等的短語來充當(dāng)。

系動詞be有各種時態(tài)的變化，也會和情態(tài)動詞連用。

(一)be的時態(tài)變化

系動詞be會有一般現(xiàn)在時、一般過去時、一般將來時、現(xiàn)在完成時、過去完成時等的時態(tài)變化。如：

He isa student.

They werein the park yesterday.

It will be cloudy tomorrow.

He has been ill for six days.

It had been three hours before she left the hat shop.

(二)be與情態(tài)動詞的連用

其用法為：情態(tài)動詞+系動詞be原形。如：

It must be Lucy's book. Her name is on the cover.

It can be very difficult for us to memorize too many words within such a short time.

She should be here on time tomorrow.

be動詞的一般現(xiàn)在時用法：

be動詞是系動詞的一種，表示“……是……”的意思?，F(xiàn)在式(The Present Forms)有am，is，are三種。這三種動詞的原形是be，所以它們稱為be動詞。

be動詞句型的構(gòu)成

肯定句：主語 + be動詞(am/is/are)...

否定句：主語 + be動詞(am/is/are) + not...

疑問句：be動詞(am/is/are) + 主語...?

疑問代詞/疑問副詞 + be動詞(am/is/are) + 主語...?

be動詞的肯定句

句型：主語 + be動詞...

be動詞的肯定句由“主語 + be動詞(am/is/are) + 表語”構(gòu)成：

I am a doctor.我是一名醫(yī)生。

Mary is at work.瑪麗在工作。

He is very brilliant.他非常聰明。

It is a nice day.今天天氣晴朗。

You are my only friend.你是我惟一的朋友。

They are students.他們是學(xué)生。

be動詞的否定句

句型：主語 + be動詞(am/is/are) + not...

be動詞一般現(xiàn)在時的否定句結(jié)構(gòu)，是在be動詞am，is，are之后加not：

We aren't her classmates.我們不是她的同班同學(xué)。

I'm not Tom.我不是湯姆。(I'm是I am的縮寫，讀作/aim/。)

It's not a cat，but a dog.這不是貓，而是狗。

Things are not always what they seem(to be).事物并不總是與表象一致。

be動詞否定句的縮寫方式：

is not的縮寫是isn't，讀作/′iznt/;are not的縮寫是aren't，讀作/a：nt/;I am～的否定句是I am not～，縮寫為I'm not～;am not不縮寫在一起。

be動詞的過去時用法：

be動詞過去時的構(gòu)成

肯定句：主語 + be動詞的過去式(was/were)...

否定句：主語 + be動詞的過去式(was/were) + not...

疑問句：be動詞的過去式(Was/Were) + 主語...?

疑問代詞/疑問副詞 + was/were + 主詞...?

be動詞過去時的肯定句

句型：主語 + was/were...

be動詞過去時由“主語 + be動詞的過去式(was/were) + 表語”構(gòu)成：

I was here yesterday.昨天我在這里。

We were hungry.我們當(dāng)時餓了。

The concert was last night.音樂會在昨晚舉行。

The biggest problem was that we didn't have enough time.最大的問題是我們當(dāng)時沒有足夠的時間。

There were some students on the campus.校園里有一些學(xué)生。

be動詞過去時的否定句

句型：主語 + was/were + not...

be動詞過去時的否定句結(jié)構(gòu)是在be動詞過去式was/were后面加上not。否定式的was not，were not大多使用縮寫形式wasn't(讀作/′w znt/)和weren't(讀作/w nt/)：

I was not here yesterday.昨天我不在這里。

He wasn't busy the other day.前幾天他不忙。

There weren't any students in the classroom.教室里一個學(xué)生也沒有。

以上就是小編給大家分享的英語語法知識，希望可以給大家在備考的時候帶來幫助。