语法专题三：状语从句1. 状语从句的类型1) 时间状语从句：常见引导词有： when：表示主句和从句的动作同时或先后发生，强调点，表“就在那时；突然”。while：常表示延续性动词或状态；while也可表示对比的转折。as soon as： 表示从句的动作一发生，主句的动作马上就发生。hardly / scarcely when；no sooner than：表示“还没来得及就；刚就”。directly, immediately, instantly：副词当连词用，表示“一就”。the moment, the minute, the second：充当连词，等于when / as soon as。each time, every time, next time, by the time等：也可以引导时间状语从句。since：引导的时间状语从句，主句常用现在完成时，从句常用一般过去时。常用句型：It is + 段时间 + since从句，“自从有多长时间了”。until：常与not连用，表示“直到才”；Not until置于句首时，主句要部分倒装；在It is / wasthat / who强调结构中，须连在一起。2) 让步状语从句：常见引导词有：although, though, even if, even though, as等。 3) 原因状语从句：常见引导词有：because：常用于回答why, 语气最强；强调原因，常与just, only等起强调作用的副词连用；可引导表语从句。for：是个并列连词，一般不放在句首，常表示一种推测或解释，或用作附加说明，语气弱。as, since：常译为“既然、由于”，表示十分明显的原因，语气较弱。now that：表示“既然”的意思。4) 地点状语从句：常见引导词有：where, wherever等。5) 目的状语从句：常见引导词有：that, so that, in order that等。目的状语从句的谓语动词常与情态动词连用，否则可能是结果状语从句。不可置于句首。目的状语从句还可以用动词不定式来替换。6) 结果状语从句：常见引导词有：that, so that, so that, such that 等。7) 方式状语从句：由as, as if(though)等引导。8) 比较状语从句：由than, as等引导。9) 条件状语从句：由if, unless, so (as) long as, in case, once, a far as, on condition that等引导。2. 注意：1) 主将从现规则：在时间状语从句、条件状语从句、让步状语从句、方式状语从句中，若主句用一般将来时，或是祈使句，或是含有情态动词的谓语形式，从句则用一般现在时表示将来时，如：You can join our club when you get a bit older.2) 疑问词 + ever和no matter + 疑问词的区别：疑问词 + ever可引导名词性从句和让步状语从句；no matter + 疑问词，只能引导让步状语从句。巩固练习：1._ youve tried it, you cant imagine how pleasant it is.A. Unless B. Because C. Although D. When 2. He left in _ a hurry _ he forgot his key. A. such, that B. so, that C. the same, as D. such, as3. He has loved me _ I were his son. A. because B. as C. if D. as though4. I dont think Ill need any money but Ill bring some _. A. as last B. in case C. once again D. in time5. Someone called me up in the middle of the night, but they hung up _ I could answer.A. as B. since C. before D. until6. We must do it well, _there are a lot of difficulties.A. as ifB. as thoughC. even thoughD. even as 7. _ has taken part in the Athens Olympic Games is worth praising no matter _ he has won medals or not.A. Who; ifB. Anyone; whether C. Whoever; whetherD. Whoever; how 8. -Its a long time _ I saw you last.-Yes, and what a pity it is now that it will be a long time _ we see each other again.A. before; sinceB. since; whenC. since; beforeD. when; before 9. The head of the company promised to deal with matters of this sort_ he returned to his office.A. until B. while C. by the timeD. the moment 10. He had already walked three or four miles_ he saw a cart by the side of the road.A. whileB. when C. the momentD. unless 11. Much _ the young couple needed money to make the down payment for the apartment, they wouldnt ask their parents for help.A. although B. as C. even if D. while 12. I have kept the photo _ I can always see it, as it reminds me of the days when I studied in Britain.A. at which B. when C. where D. at the place 13. I would appreciate it _ you can help me with my English this afternoon.A. because B. until C. when D. if 14. _ you may be right, I cant altogether agree.A. As B. While C. If D. Since 15._ was 1998 _ I graduated from the university.A. It; when B. It; that C. That; when D. That; that 16. The famous scientist grew up _ he was born and in 1930 he came to Shanghai.A. when B. whenever C. where D. wherever 17. “It gives me great joy and I feel more pressure than I did _ I won in China,” Ding Junhui said.A. that B. when C. which D. how 18. Parents should take seriously their childrens requests for sunglasses _ eye protection is necessary in sunny weather. A. because B. through C. unless D. if19. John shut everyone out of the kitchen _ he could prepare his grand surprise for the party. A. which B. when C. so that D. as if20. _ everybody knows about it, I dont want to talk any more. A. For B. Even C. Since D. However状语从句：AADBCCCCDBBCDBACBACC2