動詞是表示動作(study, find, swim 等)或狀態(tài)(be, like, feel 等)的詞。動詞具有人稱、數(shù)量、時態(tài)、語態(tài)和語態(tài)變化。
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動詞分類:動詞有助動詞、情態(tài)動詞、聯(lián)系動詞和行為動詞四類。
一)助動詞
助動詞沒有任何含義,不能單獨做謂語,只能和行為動詞一起構成謂語,幫助行為動詞組成各種時態(tài)、語態(tài)、語氣以及疑問或否定形式。常見的助動詞有be, do, does, did, have, will, shall等。具體用法如下:
1、助動詞be的用法如下:
1)構成各種進行時態(tài)。如:
It was raining all day yesterday.
昨天整天下雨。
2)構成被動語態(tài)。如:
The meeting was held yesterday afternoon.
會議是昨天下午舉行的。
3)與不定式連用表示按照計劃、預先安排或規(guī)定要發(fā)生的動作。如:
They are to see an English film this evening.
他們今天晚上看英語電影。
2、助動詞do的用法如下:
1)構成疑問式或否定式。如:
Does he think so?
I didn't say anything about the result.
2)在動詞前加上do, does, did表示強調(diào),意為"的確,確實"。如:
They do study hard.
She does love him.
He did want to help the old man.
3、have: 助動詞have 的過去式是had。have和had均可與動詞過去分詞一起構成完成時態(tài)。如:
He has lived here for three years.
As soon as the sun had set they returned.
4、shall, should: 助動詞shall只用于第一人稱的將來時態(tài);助動詞should 是shall的過去式,構成過去將來時。如:I shall send ten letters to my good friend.
She wanted to know if I should go to the palace.
二)情態(tài)動詞
情態(tài)動詞本身有一定含義,但不能單獨作謂語,要和行為動詞一起構成謂語。它們也能表明句子的否定、疑問或時態(tài)上的區(qū)別。常見的情態(tài)動詞有:can, may, must, need, should等。
表示能力
表示能力一般用can, could。如:Rose can speak now, but she couldn't a week ago.
be able to 也表示能力,它和can 的區(qū)別如下:
1)表示做事的能力,兩者可通用。但can 只能用于一般現(xiàn)在時和一般過去時。be able to 可用于任何時態(tài)。如:
She could / was able to eat four pieces of bread when she was young.
They will be able to finish the drawing soon.
2) 表示過去經(jīng)過努力而成功的某一次動作,只能用was/were able to, 但在否定句中可互換。如:
She was weak, but was able to finish the task last night.
can (could) 在疑問句中與第二人稱連用時,表示征求對方意見或提出請求,表示委婉語氣。雖然could是can的過去式,但是could 只是表示比can語氣更加委婉客氣,沒有時間上的差別。如:
-Could you lend me your pen?
-Yes, I can.
表示許可
表示許可一般用may/might, can/could, 而且??苫Q。Might, could語氣比較委婉。要特別注意:回答以might, could開頭的疑問句只能用may, can 給予直截了當?shù)幕卮稹?/p>
-Might/Could I borrow your book?
-Yes, you may/can.
表示必需、必要
must和have to都有"必須" ,一般情況下可互換。如:You must / have to finish the work..
但他們有如下區(qū)別:
1)must 表示說話人的主觀看法;have to 表示客觀需要。如:
I must have a talk with him.
He has to give up smoking because of badly cough.
2) 否定式mustn't 表示禁止,意為"不準,不可以做";don't have to 意為"不必"。如:
You mustn't hit her.
You don't have to explain it to me if you dislike the job.
注:表示推測的情態(tài)動詞有表示"一定"的must, 表示"很有可能"的should, ought to 和表示"可能"的can, could, may, might。具體用法如下:
must 表示較有把握的推測,只用于肯定句,不能用語否定句或疑問句。用法如下:
1)對目前動作的推測,用must+動詞原形。如:
You must lose in the mountain.
2) 對目前狀態(tài)的推測,用must + be + 表語。如:You speak for 4 hours, you must be thirsty.
在肯定句中,表示對現(xiàn)在或?qū)戆盐詹淮蟮耐茰y用may (might) +動詞原形,might 比 may 的可能性更??;對過去把握不大的推測用may (might) have+ 過去分詞。如:
The package might come tomorrow.
They may have killed the enemies.
3、在疑問句中,對現(xiàn)在表示推測用can (could) …+動詞原形,對過去表示懷疑則用can (could) …have+過去分詞;在否定句中,對現(xiàn)在表示推測用can't+動詞原形,對過去表示推測用can't (couldn't) have+過去分詞。如:
It can't be John. He has gone to UK.
4、need的雙重身份
need 既可作情態(tài)動詞又可作實意動詞,它們的用法不同,如不注意區(qū)分,就容易用錯。
三)系動詞
連詞動詞的種類
聯(lián)系動詞含有一定意義,它們要與其后做表語的形容詞、名詞或介詞(短語)一起構成合成謂語。系動詞按意義可分為三類,而且有自己的特定用法。
1、按意義聯(lián)系動詞有:be, appear, seem, keep, remain, continue, stay, prove 等,如:Jim appears very old.
?。?、表示感覺的聯(lián)系動詞有l(wèi)ook, feel, smell, sound, taste等。如:It smells bad.
3、表示轉變的聯(lián)系動詞有become, fall, get, go, grow, turn等。如:
She becomes more beautiful than three years ago.
四)行為動詞
行為動詞又稱實義動詞,它們都含有實在的意義,表示動作或狀態(tài),可在句中獨立作謂語。行為動詞又分為及物動詞和不及物動詞。
?。?、及物動詞
及物動詞后一定要跟賓語,意思才能完整。如:
My mother told me she wanted to buy some books for me.
2、不及物動詞
不及物動詞意義完整,不需帶賓語,但如果有些不及物動詞非要帶賓語時,必須先加介詞后加賓語。如:
He only worried about his daughter.
二、動詞的時態(tài)
動詞的時態(tài)有很多。初中階段主要掌握八種:一般現(xiàn)在時、一般過去時、現(xiàn)在進行時、過去進行時、一般將來時、過去將來時、現(xiàn)在完成時、過去完成時。
1.一般現(xiàn)在時
1)一般現(xiàn)在時態(tài)的構成:主語是I, we, you, they和名詞復數(shù)時作謂語的行為動詞用原形。主語是he, she , it和名詞單數(shù)時,作謂語的行為動詞的詞尾變化如下:
一般情況 | +s |
以s, x, ch, sh 或 o結尾 | +es |
以輔音+y結尾 | 去y變i+es |
2)一般現(xiàn)在時態(tài)的肯定句、否定句和疑問句形式(以be和like為例):
主 語 | 肯 定 式 | 否 定 式 | 疑 問 式 |
第一、二人稱和第三人稱復數(shù)以及名詞復數(shù) | I am a student. We/You/ They are students. He/ She is a student. I / We/ You/ They/ like music. Many people like music. | I am not a student. We/You/ They are not students. He/ She is not a student. I / We/ You/ They/ don’t like music. Many people don’t like music. | Are you a student. Are you/ they students? Is he/ she a student? Do you/ they like music? Do many people like music? |
3)一般現(xiàn)在時態(tài)的用法:
現(xiàn)階段經(jīng)常性,習慣性的動作 。例如:
I get up at six every morning.
He plays tennis once a week.
現(xiàn)在的狀態(tài) 例如:
My mother is a teacher. She teaches English in a school.
客觀真理 例如:
The earth goes around the sun.
4)常用于一般現(xiàn)在時態(tài)的時間狀語:
often usually sometimes always every day never in the morning 等。
例題解析:舉一反三,學的更輕松!
1. --- May I help you, sir?
--- Yes, I bought the TV the day before yesterday, but it ______.
A. didn't work B. doesn't work C. won't work D. can't work
解析:電視雖然是前天買的, 但壞了是現(xiàn)在的狀態(tài), 應該用一般現(xiàn)在時態(tài)。選B.
2.______ the bus until it ______..
A. Get off, stops B. Get off, will stop C. Don't get off, stops D. Don't get off, will stop
解析:這是一個以until引導的時間狀語從句,主句是祈使句,因此從句要用一般現(xiàn)在時表示將要發(fā)生的動作。根據(jù)句意此題應用not …until(直到……才)句型。應選C。
3.The 70-year-old man ______ exercises in the morning.
A. takes B. are taking C. took D. will take
解析:"這個70歲的老人早晨鍛煉。"這里鍛煉是一個經(jīng)常性、習慣性的動作。因此,應選A.
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