英語學習之系動詞be用法
作為系動詞(也叫連系動詞，link verb)的be，是英語學習者接觸最早的用法。下面是小編給大家分享的系動詞學習內容，大家可以作為學習的參考。
英語系動詞be用法：
(一)be的時態變化
系動詞be會有一般現在時、一般過去時、一般將來時、現在完成時、過去完成時等的時態變化。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與情態動詞的連用
其用法為：情態動詞+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.
系動詞可接哪些詞語作表語：
連系動詞后的表語通常是名詞和形容詞，有時也可以是代詞、數詞、副詞、介詞短語、不定式、動名詞、從句等。如：
1. 用名詞作表語。如：
Translation is an art. 翻譯是一種藝術。
Beijing is a beautiful city. 北京是一座美麗的城市。
2. 用形容詞表作語。如：
Traveling is interesting but tiring. 旅行是有趣的，但是使人疲勞。
Every hour and every minute is important. 每一小時，每一分鐘，都很寶貴。
3. 用代詞作表語。如：
My idea is this. 我的想法是這樣的。
Money isn’t everything. 金錢不是一切。
His latest play is nothing. 他最近出的那個劇本毫無價值。
4. 用數詞作表語。如：
Tom is 14. 湯姆14歲。
Last check-in time is 20:15. 最后檢票時間為20點15分。
The average of letters received each month is 3,000. 每月平均收到信件3,000封。
5. 用副詞作表語。如：
The secret is out. 機密泄漏了。
Sales are down. 銷售量下降了。
She is off on Saturday. 她星期六不工作。
6. 用介詞短語作表語。如：
Dinner is at six. 6點鐘開飯。
I hope he is on time. 我希望他準時。
Martha still is in hospital. 馬撒還在醫院里。
Diana was with the children. 戴安娜和孩子們在一起。
You look like your sister. 你模樣像你姐姐。
7. 用不定式作表語。如：
His goal is to be a doctor. 他的目標是當醫生。
My duty is to protect my sisters. 我的職責是保護我的妹妹們。
My advice to you is to speak the truth. 我對你的忠告是講真話。
My dream is to travel around the world. 我的夢想是環游世界。
8. 用動名詞作表語。如：
Her hobby is growing roses. 她的愛好是種植玫瑰。
His job is looking after sheep. 他的任務是看羊。
My favorite sport is swimming. 我最喜歡的運動是游泳。
9. 用從句作表語。如：
That’s what we are here for. 我們來這里就為了這個。
The question is how he did it. 問題是他是如何做此事的。
That’s where I first met her. 那就是我第一次遇見她的地方。
The trouble is that I have lost his address. 麻煩的是我把他的地址丟了。
副詞可用于系動詞后作表語嗎：
原則上說，用于系動詞后作表語要用形容詞，而不是副詞。如：
他的英語很好。
誤：His English is very well.
正：His English is very good.
這飯菜聞起來真香。
誤：The dinner smells deliciously.
正：The dinner smells delicious.
但在以下情況，副詞可用作表語(且主要是用于系動詞be后作表語)：
1. 表示地點或位置的少數副詞，如here, there, upstairs, downstairs, abroad, back等。如：
He asked if anyone was there. 他問那兒是否有人。
Are the children back yet? 孩子們回來了嗎?
Neither of them is here. 他們倆都不在這里。
She was abroad all last summer. 她去年整個夏天都在國外。
If he was downstairs, why didn’t he answer the bell? 他要是在樓下，為何不開門呢?
2. 與介詞同形的小品詞有也可用作表語，如in, on, off, out, by, away, behind, up, down, over, through, around, round, below, inside, outside 等。如：
Make sure the lid is on. 確信要把蓋子蓋上。
The engagement is off. 婚約取消了。
The taxi is outside. 出租車在外面。
The grocery was below. 雜貨店在下面。
The level of unemployment is down. 失業率在下降。
I phoned Sally but she was out. 我給薩莉打電話，可是她不在。
He hid the money when nobody was by. 附近沒人時他把錢藏了起來。
By the time we arrived the meeting was over. 我們到達時，會議已結束了。
He was left in charge of the shop while the manager was away. 經理不在時，他負責這個商店。
用于進行時態三類系動詞：
英語的系動詞通常不用于進行時態，但以下幾類有時可以這樣用：
1. 狀態系動詞
表示狀態的系動詞 be 與動態形容詞連用時，可以用于進行時態，表示特定的表現。如：
She is being very annoying this evening. 她今晚很煩人。
Your brother was being a fool yesterday. 你兄弟昨天真蠢。
I was being very careful. 我當時非常小心。
2. 感官系動詞
感官系動詞feel(感覺), look(看起來)有時可用于進行時態。如：
I’m feeling fine. 我現在感覺良好。
I’m feeling a bit lonesome. 我感到有點寂寞。
I’m glad you’re feeling so much better. 我很高興你感覺好多了。
Why is she looking so sad? 她為什么愁容滿面?
My boy is not looking very well. 我的孩子氣色不太好。
但是，當feel表示人自身的感覺時，可用于進行時態;但當它表示事物給人的感覺時，它不能用于進行時態，如以下各句不用進行時態：
Silk feels soft and smooth. 綢子摸起來柔軟光滑。
Silk feels soft and smooth. 綢緞摸起來柔軟光滑。
It felt pleasant going to work. 上班去的感覺很愉快。
3. 變化系動詞
變化系動詞become, grow, get, go, run 等有時可用于進行時態強調變化的進程。如：
The weather is getting colder. 天氣漸冷。
Her hair is going grey. 她的頭發日見花白。
Our supplies are running low. 我們的供應品不多了。
The pollution problem is growing serious. 污染問題日見嚴峻。
It was becoming cold, so we lit the fire. 天氣變冷了，于是我們就點起了火。