條件狀語(yǔ)從句

條件狀語(yǔ)從句，即在某種條件下，一件事情可能發(fā)生。在英語(yǔ)中由連接詞if或unless等引導(dǎo)的狀語(yǔ)從句叫作條件狀語(yǔ)從句。條件是指某一件事情實(shí)現(xiàn)之后(狀語(yǔ)從句中)，一件事情(主句)才能發(fā)生，通常譯作"假如，只要，如果"等意思。條件狀語(yǔ)從句中，主從句的時(shí)態(tài)要遵循"主將從現(xiàn)"的原則。即，主句是將來時(shí)態(tài)時(shí)，從句用一般現(xiàn)在時(shí)代替將來時(shí)態(tài)。

引導(dǎo)條件狀語(yǔ)從句的連詞或詞組有：if(如果)，unless(除非)，as long as(只要)等。如果主句是將來時(shí)，條件狀語(yǔ)從句也用一般現(xiàn)在時(shí)來表示。如：

I will stay at home if it rains tomorrow. 如果明天下雨，我就待在家。

You can’t learn English well unless you work hard.

除非你努力學(xué)習(xí)，否則是學(xué)不好英語(yǔ)的。

1.if引導(dǎo)的條件狀語(yǔ)從句

表示在某種條件下某事很可能發(fā)生。

If we pay much attention to the earth, we’ll have a better world.

如果我們多關(guān)愛地球，就會(huì)擁有一個(gè)更美好的世界

If it rains tomorrow, what shall we do? 如果明天下雨，我們?cè)趺崔k?

If you ask him, he will help you. 如果你請(qǐng)他幫忙，他會(huì)幫你的。

If you fail in the exam, you will let him down.

如果你考試不及格，你會(huì)讓他失望的。

注意：if還可以引導(dǎo)虛擬條件句，表示不可實(shí)現(xiàn)的條件，從句中多用一般過去時(shí)或過去完成時(shí)。

What would happen if there were no water? 如果沒有水會(huì)怎樣?

2. unless引導(dǎo)的條件狀語(yǔ)從句

unless的意思是"如果不，除非"。可與if... not互換。

You will fail in English unless you work hard.

你英語(yǔ)考試會(huì)不及格的，除非你更加努力。

You will fail to arrive there in time unless you start earlier.

如果你不早點(diǎn)動(dòng)身，你就不能及時(shí)趕到那兒。

Unless it rains, the game will be played. 除非下雨，比賽將照常進(jìn)行。

3. as /so long as引導(dǎo)的條件狀語(yǔ)從句

as /so long as的意思是"只要"

So long as you’re happy, I will be happy. 只要你高興，我就高興。

You may borrow my book as long as you keep it clean.

只要你保持書的清潔，你就可以把我的書借去。學(xué)科&網(wǎng)

4. once引導(dǎo)的條件狀語(yǔ)從句

once引導(dǎo)的條件狀語(yǔ)從句，意為"一旦……就"，從句可置于主句前或后。

Once you begin, never stop. 一旦開始，就絕不要停止。

Maths is easy to learn once you understand the rules.

一旦你理解了規(guī)則，數(shù)學(xué)就不難學(xué)了。

提示：在條件狀語(yǔ)從句中，用一般現(xiàn)在時(shí)代替一般將來時(shí)，用一般過去時(shí)代替過去將來時(shí)。

If the weather is bad next week, we’ll put off the climbing.

如果下周天氣不好，我們將推遲爬山。

Father told me if I worked hard he would buy me a gift.

爸爸告訴我，如果我努力學(xué)習(xí)，他會(huì)給我買一份禮物。

5. 引導(dǎo)條件狀語(yǔ)從句最常用的連詞是if，常見的if條件狀語(yǔ)從句表示在某條件下，某事很可能發(fā)生，條件是可能存在的，主句中某種情況發(fā)生的概率也是很高的。如：

If you ask him, he will help you. 如果你請(qǐng)他幫忙，他會(huì)幫你的。

If you fail in the exam, you will let him down.

如果你考試不及格，你會(huì)讓他失望的。

If you have finished the homework, you can go home.

如果你作業(yè)做完了就可以回家了。

另外，if從句還表示不可實(shí)現(xiàn)的條件或根本不可能存在的條件，也就是一種虛擬的條件或假設(shè)。從句多用一般過去時(shí)或過去完成時(shí)，表示對(duì)現(xiàn)在或過去的一種假設(shè)。如：

If I were you, I would invite him to the party.

如果我是你，我會(huì)邀請(qǐng)他參加聚會(huì)。

I would have arrived much earlier if I had not been caught in the traffic.

要不是交通堵塞，我本會(huì)來得早一些。

6. if 條件句的時(shí)態(tài)搭配

(1)if從句用一般現(xiàn)在時(shí)，主句用一般將來時(shí)。

If he runs he’ll get there in time. 如果他用跑的，他就會(huì)及時(shí)趕到那兒。

The cat will scratch you if you pull her tail. 如果你拉貓的尾巴，它就會(huì)抓你。

(2)if從句用一般現(xiàn)在時(shí)，主句用may/might/can。

If the fog gets thicker the plane may/might be diverted.

如果霧再大一些，飛機(jī)可能就會(huì)改在別的機(jī)場(chǎng)降落。

If it stops snowing we can go out. 如果雪停了，我們就可以出去。

(3)if從句用一般現(xiàn)在時(shí)，主句用must/should。

If you want to lose weight you must/should eat less bread.

如果你想減肥，你必須少吃面包。

(4)if從句用一般現(xiàn)在時(shí)，主句用一般現(xiàn)在時(shí)。

If you heat ice it turns to water. (也可用will turn)如果把冰加熱，它就會(huì)化成水。

(5)if從句用現(xiàn)在進(jìn)行時(shí)，主句用一般將來時(shí)。

If you are looking for Peter you’ll find him upstairs.

如果你是在找彼得，上樓就會(huì)找到他。

(6)if從句用現(xiàn)在完成時(shí)，主句用一般將來時(shí)。

If you have finished dinner I’ll ask the waiter for the bill.

如果你吃完了，我就叫服務(wù)生來算賬。

【知識(shí)拓展】

1. 在以when，before，as soon as等引導(dǎo)的時(shí)間狀語(yǔ)從句，也適用"主將從現(xiàn)"原則，即如果主句是一般將來時(shí)，從句則用一般現(xiàn)在時(shí)。

I’ll tell her the good news when she comes back.

當(dāng)她回來的時(shí)候，我將把這個(gè)好消息告訴她。

she will give you a call as soon as she returns.

她一回來就會(huì)給你電話。

2.If條件句的同義句：祈使句，and /or+將來時(shí)態(tài)的陳述句。

Work hard, and you will make great progress.

= If you work hard, you will make great progress.

如果你努力學(xué)習(xí)，你就會(huì)取得大的進(jìn)步。

Hurry up, or you will be late.

=If you don’t hurry up, you will be late.

如果你不快點(diǎn)，你就要遲到了。

【巧學(xué)妙記】

＂ if ＂ 引導(dǎo)的條件狀語(yǔ)從句的記憶口訣if 條件句不一般，幾個(gè)要點(diǎn)記心間；條件句,放在前，逗號(hào)要放句中間。條件句表真實(shí)，主將從現(xiàn)要遵從；條件句非真實(shí)，虛擬語(yǔ)氣用到位。

一、用所給詞的適當(dāng)形式填空

1. If you _______________(feel) tired, you _______________(have) to have a rest.

2. Where _______________he _______________(see) the film if he _______________(have) time?

3. If there _______________(be) fewer trees, there _______________( be) more pollution.

4. He _______________(dress) more casually if he _______________( not work) on weekends.

5. If Marcia _______________(live) alone, she _______________( keep) a pet dog.

6. Lana _______________(buy) a new dress if the old one _______________(be) out of style.

7. The twins _______________(fight) if they _______________(argue).

8. I _______________(sell) my paintings if I _______________(need) money for education.

9. Peter _______________( send) me a beautiful souvenir if he _______________(tour) Spain.

10. If Mr. Green _______________(say) I am hard-working, my parents _______________(feel) glad.

11. I _______________(go) to the beach if it _______________(not rain) this week.

12. _______________they _______________(have) a match if the P.E. teacher _______________(be) busy?

13. He _______________(write) a letter to his grandparents if he _______________(get) his report card this week.

14. If she _______________(get) up late, she _______________(not catch) the early bus.

15. Peter _______________(major) in English if he _______________(pass) the exams in Peking University.

二、完成句子

1. 如果他到的晚了會(huì)發(fā)生什么事情?

What _______________ _______________if he _______________late?

2. 如果努力學(xué)習(xí)，你就會(huì)取得好成績(jī)。

If you _______________ _______________, you _______________ _______________ _______________ _______________.

3. 他如果看電視太久了，他的父母會(huì)不高興。

If he _______________ TV too much, his parents _______________ _______________ unhappy.

4. 如果我們?yōu)樗�組織生日聚會(huì)，大家都會(huì)來的。

Everyone _______________come if we _______________a birthday party _______________him.

5. 如果明天不下雨，我會(huì)和你一起去公園的。

If it _______________ _______________tomorrow, I _______________go to the park _______________you.

6. 如果她起晚了，就會(huì)旅游遲到。

She ______________ ______________ ______________ ______________ the trip if she ______________ ______________ late

7. 如果他有空，他會(huì)幫助你的。

If he _______________ _______________, he _______________ _______________you.

8. 如果Tom成為足球運(yùn)動(dòng)員，他就不會(huì)上大學(xué)了。

Tom _______________ _______________go to the college if he _______________a soccer player..

9. 你如果不完成作業(yè)就不能學(xué)好各門功課。

You _______________ _______________good at all the subjects if you _______________finish the homework.

10. 如果你上課睡覺，老師會(huì)生氣。

If you _______________in class, your teacher _______________ _______________ _______________.

1. (2018 • 菏澤中考)—I really want to pass the exam for further study.

—Believe in yourself, dear! Your dream will came true ___________ you put your heart into it.

A. even if B. as long as C. as soon as

2. (2018 • 安順中考)—The weather report says that it ___________ tomorrow in most parts of Anshun city.

—If it ___________, the school sports meet will be canceled.

A. will rain; will rain B. will rain; rains

C. rains; will rain D. rains; rains

3. (2018 • 恩施中考)If you are caught smoking in the kitchen, you ___________ by your boss.

A. will fire B. are fired C. will be fired

4. (2018 • 江西中考)—Can students go online during lessons?

—They can ___________ it is for that lesson.

A. if B. or C. so D. but

5. (2018 • 四川樂山中考)—Thank you for telling me so much knowledge about nature.

—Don’t mention it. ___________ you have more questions, come to me any time.

A. If B. Because C. Though

6. (2018 • 菏澤中考)—I really want to pass the exam for further study.

—Believe in yourself, dear! Your dream will came true you put your heart into it.

A. even if B. as long as C. as soon as

7. (2017﹒海南)I won’t talk about that with Kate ___________ she wants.

A. because B. unless C. after

8. (2017﹒江蘇宿遷)Our head teacher often says, "You will not pass the exam ___________ you work hard."

A. if B. unless C. since D. when

9. (2017﹒黑龍江哈爾濱)—I wonder if our foreign teacher Mr. White ___________ to his hometown next Tuesday.

—I’m not sure. But if he returns to his hometown, I’ll ___________ him off.

A. return;see B. will return;see C. will return;will see

10. (2017﹒江蘇蘇州)You will never achieve success ___________ ou devote yourself to your work.

A. after B. if C. because D. unless

11. (2017﹒廣東)Johnson won’t answer the phone if he ___________ the number.

A. knew B. doesn’t know C. will know D. didn’t know

12. (2017﹒江蘇鹽城)You will be able to see something ______ you climb onto those rocks.

A. if B. though C. until D. unless

1. (安徽省亳州市利辛縣2018屆九年級(jí)10月月考)You won’t get to the subway station before 9 :00 am _______________ you leave earlier.

A. unless B. until C. because D. when

2. (黑龍江杜爾伯特縣蒙古族中學(xué)2018屆九年級(jí)(五四學(xué)制)上學(xué)期期中)If New Mart _______________ 24 hours a day during the winter holiday, I will feel _______________.

A. is open;excited B. is open;exciting

C. will open;excited D. will open;exciting

3. (云南省馬龍縣通泉鎮(zhèn)中學(xué)2017屆九年級(jí)下學(xué)期第一次模擬)I won’t be able to understand what you say, you speak too quickly.

A. if B. though C. because D. but

4. Lucy and I have been friends for years. _______________ my memory is correct, we first met in a meeting.

A. If B. Because C. Though D. When

5. (廣東省東莞市2017屆中考沖刺考前押題)I think you should complain _______________ you are happy with the situation.

A. unless B. however C. after D. though

6. (江蘇省揚(yáng)州市江都區(qū)2017屆中考第二次模擬)I will have to close my clothes shop _______________ my business improves.

A. if B. unless C. after D. when

7. Chuck will go swimming with us tomorrow afternoon _______________ he can finish his homework by then.

A. so B. but C. if D. or

8. _______________ you have a picnic this weekend, remember to call me.

A. As B. For C. If D. Because

9. (江蘇省鹽城市毓龍路實(shí)驗(yàn)學(xué)校2017屆九年級(jí)中考第一次模擬)I usually sleep with the window open ______________ it’s very cold.

A. until B. as C. if D. unless

10. (江蘇省徐州市部分學(xué)校2017屆九年級(jí)二模聯(lián)考)—Could you give me some advice on travelling?

—Take a map with you _______________ you have a guide or you know the city well.

A. if B. unless C. although D. because

11. (上海市華東師范大學(xué)第二附屬中學(xué)2017屆九年級(jí)下學(xué)期周測(cè))It is seven o’clock. You will be late for school _______________ you get up right now.

A. unless B. until C. when D. though

12. —Excuse me, could you please tell me if the meeting _______________ on time?

—If it _______________ tomorrow, we’ll have to put it off.

A. will hold;snows B. will be held;snows

C. will be held;snow D. holds;will snow

跟蹤訓(xùn)練

一、用所給詞的適當(dāng)形式填空

1. feel;will have 2. will;see;has 3. are;will be 4. will dress;doesn’t work

5. lives;will keep 6. will buy;is 7. will fight;argue 8. will sell;need

9. will send;tours 10. says;will feel 11. will go;doesn’t rain 12. Will;have;is

13. will write;gets 14. gets;won’t catch 15. will major;passes

二、完成句子

1. will happen;is 2. study hard;will get good grades 3. watches;will be

4. will;organize;for 5. doesn’t rain;will;with 6. will be late for;gets up

7. is free;will help 8. will never;becomes 9. won’t be;don’t

10. sleep;will be angry

真題再現(xiàn)

1. B【解析】句意：——我真的想通過考試，繼續(xù)深造。——相信你自己，親愛的!只要你用心去做，你的夢(mèng)想就會(huì)成真。考查連詞辨析題。A. even if即使，表讓步;B. as long as只要，表?xiàng)l件;C. as soon as一…就…。本句是條件狀語(yǔ)從句，需用as long as連接。根據(jù)句意語(yǔ)境，可知選B。

3. C【解析】句意：如果你在廚房里被抓到吸煙，你就會(huì)被老板開除。你只能“被開除”，所以需要使用被動(dòng)語(yǔ)態(tài)be done，如果主句是將來時(shí)，那么if引導(dǎo)的條件狀語(yǔ)從句用一般現(xiàn)在時(shí)表將來，這是主將從現(xiàn)的用法，本題中從句是說如果被抓到抽煙的話，用了一般現(xiàn)在時(shí)，那么主句用一般將來時(shí)，表示“你將會(huì)被開除”，所以用一把將來時(shí)的被動(dòng)語(yǔ)態(tài)，will be done，故選C，

4. A【解析】句意：——學(xué)生可以在課上上網(wǎng)嗎?——如果是為了上課，他們可以上網(wǎng)。考查連詞辨析題。if如果，表?xiàng)l件;or或者，表選擇;so所以，表結(jié)果;but但是，表轉(zhuǎn)折。答句是條件狀語(yǔ)從句，需用if連接。根據(jù)句意結(jié)構(gòu)，可知選A。

5. A【解析】句意：——謝謝你告訴我這么多關(guān)于自然的知識(shí)。——別提了。如果你有更多的問題，隨時(shí)找我。考查連詞辨析題。本句是條件狀語(yǔ)從句，需用if連接，而because表原因，though表讓步，都可排除。根據(jù)句意結(jié)構(gòu)和語(yǔ)境，可知選A。

6. B【解析】句意：——我真的想通過考試，繼續(xù)深造。——相信你自己，親愛的!只要你用心去做，你的夢(mèng)想就會(huì)成真。考查連詞辨析題。A. even if即使，表讓步;B. as long as只要，表?xiàng)l件;C. as soon as一…就…。本句是條件狀語(yǔ)從句，需用as long as連接。根據(jù)句意語(yǔ)境，可知選B。

7. B 【解析】句意：我不想和凱特談那個(gè)，除非她愿意。A. because連詞，因?yàn)椋�引�?dǎo)原因狀語(yǔ)從句;B. unless連詞，除非，引導(dǎo)條件狀語(yǔ)從句;C. after連詞，在……之后，引導(dǎo)時(shí)間狀語(yǔ)從句。根據(jù)后文是前文的"條件"，所以使用unless。故選：B。

8. B 【解析】句意：我們的班主任常說："如果你們不努力學(xué)習(xí)，你們就通不過考試"。If如果，引導(dǎo)條件狀語(yǔ)從句;unless除非，引導(dǎo)條件狀語(yǔ)從句;since自從，因?yàn)椋�引�?dǎo)時(shí)間狀語(yǔ)從句;when當(dāng)……時(shí)候，引導(dǎo)時(shí)間狀語(yǔ)從句;條件狀語(yǔ)從句用一般現(xiàn)在時(shí)表示一般將來時(shí)，主句用一般將來時(shí)，根據(jù)題中的時(shí)態(tài)和句意，如果不努力，就通不過考試，故此處用unless。故選B。

10. D 【解析】句意：除非你把自己專心于你的工作，否則你將永遠(yuǎn)不會(huì)成功。句意：after在……之后;if如果，because因?yàn)椋瑄nless除非，如果不;if或unless引導(dǎo)的條件狀語(yǔ)從句用一般現(xiàn)在時(shí)表示一般將來時(shí)，主句用一般將來時(shí)。結(jié)合句意，你如果不專心工作，你就不會(huì)獲得成功，故此處為unless。故選D。

11. B 【解析】句意：如果約翰遜不知道電話號(hào)碼，他就不接電話。本句是if引導(dǎo)的條件狀語(yǔ)從句，當(dāng)主句是將來時(shí)態(tài)時(shí)，從句用一般現(xiàn)在時(shí)，可排除C、D兩項(xiàng)。根據(jù)句意，本句是否定陳述，故選B。

12. A 【解析】句意：如果你爬上這些巖石，你就會(huì)看到一些東西。A如果，引導(dǎo)條件狀語(yǔ)從句;B即使，引導(dǎo)讓步狀語(yǔ)從句;C直到……;D如果……不。故選A。學(xué)科&網(wǎng)

模擬檢測(cè)

1. A 【解析】句意：除非你早點(diǎn)離開，否則你在九點(diǎn)之前不會(huì)到達(dá)地鐵站。A. unless除非……;B. until直到……;C. because因?yàn)?hellip;…;D. when什么時(shí)間。根據(jù)題意，除非你早點(diǎn)離開，所以連接詞用unless。故正確答案為A。

2. A 【解析】句意：如果新瑪特在寒假期間一天24小時(shí)營(yíng)業(yè)，我將會(huì)感到很激動(dòng)。if引導(dǎo)的條件狀語(yǔ)從句不用將來時(shí)態(tài)，用一般現(xiàn)時(shí)態(tài)來代替;excited形容詞，主要指人感到激動(dòng);exciting形容詞，主要指令人激動(dòng)的事，故選A。

3. A 【解析】句意：如果你說得太快，我將不能理解你說的話。A. if 如果;B. though 盡管;C. because 因?yàn)?D. but但是。這里是主將從現(xiàn)，if后引導(dǎo)的是一般現(xiàn)在時(shí)，主句用的是一般將來時(shí)。故選A。

4. A 【解析】句意：Lucy和我是多年的好朋友，如果我的記憶沒錯(cuò)，我們第一次見面是在一次會(huì)議上。if如果，引導(dǎo)條件狀語(yǔ)從句;because因?yàn)椋�引�?dǎo)原因狀語(yǔ)從句;though盡管，引導(dǎo)讓步狀語(yǔ)從句;when當(dāng)……時(shí)候，引導(dǎo)時(shí)間狀語(yǔ)從句。根據(jù)句意可知，這里表示條件，故應(yīng)選A。

6. B 【解析】句意：除非我的生意有起色，否則我要關(guān)閉我的服裝店。A.如果;B.除非;C.在……之后;D.當(dāng)……時(shí)候。故選B。

7. C 【解析】句意：明天下午Chuck將和我們一起去游泳，如果到那時(shí)他能完成他的作業(yè)的話。so所以;but但是;if如果;or或者。If引導(dǎo)的條件狀語(yǔ)從句用一般現(xiàn)在時(shí)，主句用一般將來時(shí)，故選C。

8. C 【解析】句意：如果這個(gè)周末你去野餐，記得給我打電話。As當(dāng)……時(shí)候;for因?yàn)?if如果;because因?yàn)椤８鶕?jù)this weekend可知此處對(duì)這個(gè)周末的假設(shè)，故用if引導(dǎo)的條件狀語(yǔ)從句，故選C。

9. D 【解析】句意：除非天冷，否則我們都開窗睡覺。A.直到……;B.當(dāng);C.如果;D.除非。根據(jù)句意，故選D。

10. B 【解析】句意：——你能給我一些關(guān)于旅行的建議嗎?——如果沒有向?qū)Щ蛘邔?duì)城市不很了解，那么就隨身帶著一張地圖。A. if如果;B. unless除非，如果不;C. although雖然，盡管;D. because因?yàn)椤９蔬xB。

11. A 【解析】句意：現(xiàn)在7點(diǎn)了，如果你現(xiàn)在不起床你就會(huì)上學(xué)遲到了。A. unless除非;B. until 直到……; C. when當(dāng)……時(shí)候;D. though盡管。故選A。

12. B 【解析】句意：——對(duì)不起，請(qǐng)你告訴我會(huì)議是否將如期舉行?——如果明天下雪，我們將不得不推遲。在問句中if 表示"是否"，引導(dǎo)賓語(yǔ)從句，而the meeting和hold是被動(dòng)關(guān)系，故應(yīng)該使用一般將來時(shí)的被動(dòng)語(yǔ)態(tài)。答句中的if表示"如果"，引導(dǎo)條件狀語(yǔ)從句，主句用一般將來時(shí)，從句常用一般現(xiàn)在時(shí)表將來，故選B。

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