1、It 特殊用法連詞 含義及用法 例句before在之前。表示主句的動作發生在從句的動作之前They need to think before they act and make good decisions for themselves. when當的時候；引導的從句可以用延續性動詞，也可以用短暫性動詞When it began to rain, Ben was helping his mom make dinner. 1.引導時間狀語從句連詞 含義及用法 例句while正當時；正在時。引導的從句中，謂語動詞必須是延續性動詞，且常用進行時While John was taking photos

2、, Mary bought a drink. as當時。表示一件事情正在發生，另一件事情也在進行中，通常只用于一般過去As time passed, things seemed to get better.after在之后。表示主句的動作發生在從句的動作之后He became an English teacher after he graduated from school. 連詞 含義及用法 例句until / till直到。常用在“not.until.” 結構中，表示“直到才”Im really tired because I studied until midnight last nig

3、ht. since自以來。主句用現在完成時，從句用一般過去時Youve been happy since I first met you. as soon as一就。引導的從句常用一般現在時，主句用一般將來時I will give you a call as soon as I arrive home.連詞 含義及用法 例句if “如果”。從句用一般現在時，主句通常用一般將來時 If he practices it, his handwriting will certainly improve2.引導條件狀語從句連詞 含義及用法 例句unless “如果不，除非”。unless可以轉化為if.

4、not.結構。主從句時態與if用法一致 Unless you get enough sleep every night, you will not remember things well. as long as“只要”。主從句時態與if用法一致 You wont have to worry about the final exam as long as you work hard. 連詞 含義及用法 例句though雖然。引導讓步狀語從句時，不能與but同時使用Though we are going to part, our friendship will always remain.3.

5、引導讓步狀語從句連詞 含義及用法 例句although盡管。引導讓步狀語從句時，不能與but同時使用Although milk is good, you should not drink too much of it. even though/if即使。引導讓步狀語從句時，不能與but同時使用 Even though I am sad that junior high is over, I look forward to new experiences in senior high!4.引導原因狀語從句連詞含義及用法例句because因為，表示造成某種情況的直接原因，回答why引導的問句，不能

6、和so同時使用I often exercise at the park because I love the clean air and sunshine. since既然，語氣比because弱，表示對方已知或眾所周知的原因Since we have no idea about this problem, lets ask Mr. Wang for help. as由于，因為。語氣比since弱，表示眾所周知的原因，引導的從句位于主句前后均可As it was getting late, I decided to leave now. 5.引導方式狀語從句連詞 含義 例句as照的方式You

7、will work out this problem faster if you do as what I told you. as if/ though似乎，好像Everything in my childhood crowded in my mind as if they had just happened. 6.引導結果狀語從句連詞含義用法例句so.that. 如此以至于 so修飾的中心詞是形容詞或副詞，結構為“soadj./adv.that.”。可與too.to結構互換He was so angry that he couldnt say a word. He was too angr

8、y to say a word. 連詞含義用法例句such.that. 如此以至于 such修飾的中心詞是名詞，結構為“sucha/anadj.可數名詞單數that.”或者“suchadj.不可數名詞/可數名詞復數that.”She is such a lovely girl that everyone around her likes her.She is so lovely that everyone around her likes her.7.引導目的狀語從句連詞短語含義及用法例句so that“以便”。后接從句，只能用于句中 They sped up so that / in ord

9、er that they could get there on time.in order that“為了”。后接從句，可用于句首或句中練一練1. A car suddenly appeared around the corner _ the lights were changing to red.A. after B. before C. while D. until3. _ my grandpa is over 80 years old, he still looks strong and healthy.A. Although B. Because C. Unless D. SinceC

10、A2. Mom wont let Dick go out _ he promises to be back by 10：00 tonight.A. if B. when C. since D. unlessD1.主將從現：主句用一般將來時，從句用一般現在時If it rains tomorrow, I will not go to the park. 2.主祈從現：主句是祈使句時，從句用一般現在時Please let me know if he comes.3.主情從現：主句有情態動詞時，從句用一般現在時You should eat something if you feel hungry.在時間狀語從句和條件狀語從句中，主句和從句的時態一致問題一般有三種情況： 1. -What will Bill do if he _in the test? -He will try again.fail B. fails C. will fail D. is failing 2. Please tell her the news when she_. OK, I will. A. comes B. will come. C. come D. would come 3