状语从句之条件状语从句

1、conditional clauseDefinition:A type of adverbial clause that states a hypothesis or condition, real or imagined.A conditional clause may be introduced by the subordinating conjunction if or another conjunction, such as unless, provided that,or in case of.Like other

2、 adverbial clauses, a conditional clause can come either before or after the clause on which it states a condition.Examples and Observations:"If you want a friend in Washington, get a dog."(Harry Truman)"If we had no winter, the spring would not be so pleasant; if

3、we did not sometimes taste of adversity, prosperity would not be so welcome."(Anne Bradstreet, "Meditations Divine and Moral")"Romans park their cars the way I would park if I had just spilled a beaker of hydrochloric acid on my lap."(Bill Bryson, Neither Here

4、 Nor There: Travels in Europe. William Morrow, 1992)· "If I had only known, I would have been a locksmith."(Albert Einstein)· "Conditions deal with imagined situations: some are possible, some are unlikely, some are impossible. The speaker/writer imagines that some

5、thing can or cannot happen or have happened, and then compares that situation with possible consequences or outcomes, or offers further logical conclusions about the situation."(R. Carter, Cambridge Grammar of English. Cambridge Univ. Press, 2006)· Types of Conditional ClausesThere ar

6、e six main types of conditional sentence:1. For example, the equilibrium between liquid and vapor is upset if the temperature is increased.(General rule, or law of nature: it always happens.)2. If you start thinking about this game, it will drive you crazy.(Open future condition: it m

7、ay or may not happen.)3. But if you really wanted to be on Malibu Beach, you'd be there.(Unlikely future condition: it probably won't happen.)4. If I were you, I would go to the conference center itself and ask to see someone in security.(Impossible future condition: it could

8、never happen.)5. "I would have resigned if they had made the decision themselves," she said.(Impossible past condition: it didn't happen.)6. If he had been working for three days and three nights then it was in the suit he was wearing now.(Unknown past condition: we don&

9、#39;t know the facts.)(John Seely, Grammar for Teachers. Oxpecker, 2007)These type of clauses are often called "if clauses" in English grammar books and follow conditional sentence patterns. Take a look at the chart below to study the various usage of different time expressions.Punctu

10、ationWhen an adverb clause begins the sentence use a comma to separate the two clauses.Example: If he comes, we will have some lunch. When the adverb clause finishes the sentence there is no need for a comma. Example: He would have invited me if he had known.More information on the co

11、rrect tense usage for the conditionalsIf· If we win, we'll go to Kelly's to celebrate!· She would buy a house, if she had enough money.'If' clauses express the conditions necessary for the result. If clauses are followed by expected results based on the condition. More

12、 information on the correct tense usage for the conditionalsEven if· Even if she saves a lot, she won't be able to afford that house.In contrast to sentences with 'if' sentences with 'even if' show a result that is unexpected based on the condition in the 'even if' c

13、lause. Example: COMPARE: If she studies hard, she will pass the exam AND Even if she studies hard, she won't pass the exam.Whether or not· They won't be able to come whether or not they have enough money.· Whether they have money or not, they won't be able to come.

14、9;Whether or not' expresses the idea that neither one condition or another matters; the result will be the same. Notice the possibility of inversion (Whether they have money or not) with 'whether or not'.Unless· Unless she hurries up, we won't arrive in time.· We won't

15、go unless he arrives soon.'Unless' expresses the idea of 'if not' Example: Unless she hurries up, we won't arrive in time. MEANS THE SAME AS: If she doesn't hurry up, we won't arrive in time. 'Unless' is only used in the first conditional.In case (t

16、hat), in the event (that)· In the case you need me, I'll be at Tom's.· I'll be studying upstairs in the event he calls.'In case' and 'in the event' usually mean that you don't expect something to happen, but if it does. Both are used primarily for future eve

17、nts.Only if· We'll give you your bicycle only if you do well on your exams.· Only if you do well on your exams will we give you your bicycle.'Only if' means 'only in the case that something happens - and only if'. This form basically means the same as 'if'. Howe

18、ver, it does stress the condition for the result. Note that when 'only if' begins the sentence you need to invert the main clause.Second ConditionalIntroductionThe second conditional (also called conditional type 2) is a structure used for talking about unreal situations in the pre

19、sent or in the future. This page will explain how the second conditional is formed, and when to use it.The structure of a second conditional sentenceLike a first conditional, a second conditional sentence consists of two clauses, an “if” clause and a main clause:“If” clauseMain clauseIf I had a

20、 million dollars,I would buy a big house.If the “if” clause comes first, a comma is usually used. If the “if” clause comes second, there is no need for a comma:Main clause“If” clauseI would buy a big houseif I had a million dollars.We use different verb forms in each part of a second conditional:“If

21、” clauseif + subject + simple past verb*Main clausesubject + would + verb*Note that this "simple past" form is slightly different from usual in the case of the verb BE. Whatever the subject, the verb form is "were", not "was": If I were rich, I'd buy a big house.Usi

22、ng the second conditionalThe second conditional is used to talk about things which are unreal (not true or not possible) in the present or the future - things which don't or won't happen:ExampleExplanationIf I were you, I would drive more carefully in the rain.I am not you this is unreal.Pau

23、la would be sad if Jan left.Jan will not leave that's not going to happen.If dogs had wings, they would be able to fly.Dogs don't have wings that's impossible. When you are sure that you understand the lesson, you can continue with the exercises.Second Conditional 1All of these sent

24、ences are second conditionals. Choose the correct form of the verb in each question.1. If there _ no mosquitos, there would be no malaria.A.   ?    wereB.   ?    areC.   ?    isD.   ?   

25、; wasE.   ?    would be2. If I _ a penny for every can of soda I've drunk in my life, I would be rich!A.   ?    will haveB.   ?    haveC.   ?    hadD.   ? &

26、#160;  would have3. If he were a young man, he _ able to walk faster.A.   ?    isB.   ?    wasC.   ?    will beD.   ?    would be4. If her hair were black, she _ complete

27、ly different.A.   ?    looksB.   ?    would lookC.   ?    lookD.   ?    will look5. We'd be on the beach if we _ in Mexico!A.   ?    would beB. &#

28、160; ?    will beC.   ?    wereD.   ?    are6. If the weather _ better, we _ to the park.A.   ?    is. would goB.   ?    were. will goC.   ? 

29、;   was. goD.   ?    were. would go7. We would learn a lot from dolphins if they _.A.   ?    can talkB.   ?    will talkC.   ?    talkD.   ?  

30、60; could talk8. He's so stupid! If he _ an animal, he would be a sheep.A.   ?    wasB.   ?    wereC.   ?    isD.   ?    would beE.   ?    ar

31、e9. If smoking were allowed, I _ a cigarette.A.   ?    would haveB.   ?    haveC.   ?    hadD.   ?    will have10. We don't mind camping, but if we _ enough money, we _ in a ho

32、tel.A.   ?    had. would stayB.   ?    have. stayedC.   ?    had. stayedD.   ?    would have.stayedNext exerciseSecond Conditional 2Type the correct form of each verb.Each of these

33、 sentences is a second conditional. Complete the sentences by typing the correct form of each verb in brackets. 1. If Joe  (be) here, he  (catch) some fish for supper.2. It  (be) nice if the rain  (stop)!3. I  (sing) you a song if I  (

34、have) my guitar.4. If I  (have) a better sleeping bag, I  (not feel) so cold.5. If this tent  (be) any smaller, one of us  (have to sleep) outside!6. I  (look) out for bears if I  (be) you!7. If I  (not be) so hungry, I  

35、;(share) my beans with you.Third ConditionalIntroductionThe third conditional (also called conditional type 3) is a structure used for talking about unreal situations in the past. This page will explain how the third conditional is formed, and when to use it.The structure of a third condit

36、ional sentenceLike the other conditionals, a third conditional sentence consists of two clauses, an “if” clause and a main clause:IF clausemain clauseIf I had studied harder,I would have passed the exam.Explanation: I failed the exam, because I didn't study hard enough.If the “if” clause co

37、mes first, a comma is usually used. If the “if” clause comes second, there is no need for a comma:main clauseIF clauseI probably would have passed the examif I had studied harder.We use different verb forms in each part of a third conditional:IF clauseif + subject + past perfect verb*main clausesubj

38、ect + would (OR could, OR might) have + past participle*The past perfect is formed with the auxiliary verb “had”, and the past participle (or third form) of the verb.Note also that third conditional forms can be contracted:Full formIf I had studied harder, I probably would have passed the exam.Contr

39、acted formIf I'd studied harder, I probably would've passed the exam. Using the third conditionalThe third conditional is used to talk about things which did not happen in the past. If your native language does not have a similar construction, you may find this a little strang

40、e, but it can be very useful. It is often used to express criticism or regret:ExampleExplanationIf you had driven more carefully, you would not have had an accident.Criticism: You had an accident because you didn't drive carefully enough.If we had played a little better, we could have won the ga

41、me.Regret: We didn't play well, so we lost the game.If you had saved your money, you could have bought a computer.Criticism: You didn't save your money, so now you can't afford a computer.If it had snowed, we could have gone skiing.Regret: It didn't snow, so we couldn't go skiing

42、. Third ConditionalIntroductionWe use Third Conditional (also known as the past hypothetical conditional) to talk about or write about past unreal situations, past situations that didn't actually happen. Since neither action took place, the condition is unreal.Consider the followi

43、ng examples.If I had not spent all my money, I would have lent you some.Meaning: I spent all my money earlier, so I wasn't able to lend you any.If we had not been so hungry, we would not have eaten such a large meal.Meaning: We were very hungry, so we ate a large meal.Forming the Third Condition

44、alFormationLike the other conditionals, a third or hypothetical conditional sentence consists of two clauses, an "if" clause and a main clause: Consider these examples.If I had had time, I would have helped you.Meaning: I wanted to help you, but I couldn't because I

45、 didn't have enough time.If the street had not been so icy, the accident could have been avoided.Meaning: The street was icy, so the drivers weren't able to avoid hitting each other.We use different verb forms in each part of a third conditional:If ClauseMain Clauseif + subject + past p

46、erfect verb*subject + would (OR could, OR might) have + past participle*The past perfect is formed with the auxiliary verb "had", and the past participle (or third form) of the verb.Note also that third conditional forms can be contracted:Full formIf I had studied harder, I probably would

47、have passed the exam.Contracted formIf I'd studied harder, I probably would've passed the exam.Conditional AuxiliariesThere are four conditional auxiliaries: would, could, might, and should.WouldThe conditional auxiliary would is used to indicate probability or

48、intention. See the following example.ExampleMeaningI would have applied for the position if I had had the proper qualifications.I wanted the new position, but I didn't apply for it because I didn't have the proper qualifications.CouldThe conditional auxiliary could is used to indic

49、ate hypothetical ability or possibility, as in these two examples.ExampleMeaningIf our team had practiced more, we could have played better.Past ability: We did not practice enough, so we didn't play as well as we could have.If I had come by car, I could have given you a ride home.Past possibili

50、ty: I did not come by car, so I could not give you a ride home.MightThe conditional auxiliary might is used to indicate less certain possibility, as in this example.ExampleMeaningIf Nancy had needed more money, she might have looked for a part-time job, or asked the bank for a loan.Either

51、option is possible.* NoteSometimes there is a connection between past hypothetical conditionals and the present. Consider these examples.If nobody had invented rock music, what would music be like today?If the Wright brothers had not invented the airplane, how would people travel great distances qui

52、ckly today? Third ConditionalIn this exercise, you will practise forming the third conditional. Based on the example sentence, complete the third conditional sentence by filling in the spaces. For example:I didn't pass the test, because I hadn't studied hard enough. -> "If I had stud

53、ied harder, I would have passed the test."1. He crashed his car, because he fell asleep while driving.If he  asleep while driving, he  his car.2. We couldn't go to the concert, because we didn't have enough money.If we  enough money, we  to the co

54、ncert.3. I lost my job because I was late for work.I  my job if I  late for work.4. The wind was so strong that the bridge collapsed.If the wind  so strong, the bridge .5. I couldn't call Sally because I had lost her number.I  Sally if I  he

55、r number.Third Conditional 1Choose the correct answer to complete each sentence.1. If the paramedics had not arrived so quickly, _A.   ?    the accident victim didn't survive.B.   ?    the accident victim might not have survived.C. 

56、0; ?    the accident victim might have survived.2. If you had edited your essay before handing it in, _A.   ?    you made so many mistakes.B.   ?    you wouldn't have made so many mistakes.C.   ? 

57、   you wouldn't make so many mistakes.3. If innovative musicians like Buddy Holly and Jimi Hendrix had not died so young, _A.   ?    I wonder what the music scene would be like today.B.   ?    I wonder what will the music

58、 scene be like today.C.   ?    I wonder what the music scene is like today.4. If the government had eliminated the deficit, _A.   ?    our taxes would have been reduced.B.   ?    our taxes could be reduced.C. &

59、#160; ?    our taxes will have been reduced.5. There probably would have been more casualties _A.   ?    if people at the scene were calm.B.   ?    if people at the scene had stayed calm.C.   ?  

60、  if people at the scene had not stayed calm.6. If I had gone to university, _A.   ?    I would have studied medicine.B.   ?    I have studied medicine.C.   ?    I would study medicine.7. If you had n

61、ot found that missing file, _A.   ?    the company might not have lost a lot of money.B.   ?    the company might have lost a lot of money.C.   ?    the company lost a lot of money.8. Had she not topped the lis

62、t of hopeful job candidates, _A.   ?    we didn't offer her the position.B.   ?    we would not offer her the position.C.   ?    we would not have offered her the position.9. If I had known more details abo

63、ut the position, _A.   ?    I would do better at the interview.B.   ?    I did better at the interview.C.   ?    I could have done better at the interview.10. If we had not shopped for so long, _A.   

64、?    we could have been home by now.B.   ?    we have been home by now.C.   ?    we had been home by now.Third Conditional 2Choose the correct answer to complete each sentence.1. I wonder how things would have been diffe

65、rent _A.   ?    if Edison had not invented the electric light.B.   ?    if Edison would not have invented the electric light.C.   ?    if Edison didn't invent the electric light.2. If I had not had the supp

66、ort of my friends, _A.   ?    I don't know what to do.B.   ?    I don't know what I would do.C.   ?    I don't know what I would have done.3. If the driver had not been going too fast, _A.  

67、60;?    he might have avoided hitting the other car.B.   ?    he should have avoided hitting the other car.C.   ?    he might avoid hitting the other car.4. If the table had not been so heavy, _A.   ? 

68、0;  I will move it by myself.B.   ?    I would move it by myself.C.   ?    I could have moved it by myself.5. If the fire department had not responded so quickly, _A.   ?    The house will have burned

69、 down.B.   ?    the house could have burned down.C.   ?    the house would burn down.6. He might not have lost his money _A.   ?    if he would not have invested it unwisely.B.   ?    if he were to invest it wisely.C.   ?    if he