初中英語從句語法講解

1、從句從句按其在復合句中的作用,分為主語從句、表語從句、賓語從句、定語從句和狀語從句等。（參見以下各條）3、各從句在句子中的位置以及用法：(1) 表語從句：在句子中作連系動詞的表語的從句,它位于主句中的系動詞之后。 例如：That is why he did not come to school yesterday. / It is because you are so clever.(2) 賓語從句：在句子中作及物動詞或介詞的賓語。基本形式：（主句）連詞+從句主語+從句謂語+. 關于賓語從句連詞的選擇：若從句來源于一個陳述句,那么,連詞用that,在口語中that可以省略; 若從句來源于一個一

2、般疑問句,連詞則用if 或whether; 若從句來源于一個特殊疑問句,則連詞就是疑問詞(如what,who,where,when等)例如：They believe that the computer will finally take the place of human beings.(他們相信計算機終將代替人類。) (從句本來就是陳述句)/ I wonder whether I should say something for him to the headmaster. (我不知道是不是該為他在校長跟前說點什么。) (從句來源于一般問句Shall I say something for

3、 him to the headmaster?) / He asked me where he could get such medicine. (他問我在哪兒能搞到那樣的藥。) (從句來源于特殊問句Where can he get such medicine? ) 賓語從句的時態(tài)問題：如果主句是現(xiàn)在時,從句則用現(xiàn)在某一時態(tài),甚至可以用過去時；如主句是過去時,從句則相應地使用過去某一時態(tài),遇到客觀真理時仍然用現(xiàn)在時。如：I think I will do better in English this term. (我想本學期我的英語會學得好點。) / The teacher asked the

4、 boy if the earth is round. (老師問那個男孩地球是不是圓的。) 下列結構后面的從句一般也作為賓語從句看待： be sorry / afraid / sure / glad +that從句,如：Im sorry Im late. (對不起,我遲到了。) / Im afraid he isnt in at the moment. (恐怕他此刻不在家。)(3) 狀語從句：在復合句中作狀語,其位置可以在主句前或主句后。狀語從句可以分為時間、地點、原因、目的、結果、比較、讓步、條件等幾種。狀語從句由從屬連接詞引導。時間狀語從句通常由when ,as ,while, after

5、, before, since, as soon as ,since, till (until), while, whenever 等引導。時間狀語從句一般放在句首或句尾,特別注意,時間狀語從句不允許使用將來時,而應該用現(xiàn)在時替代。如： When you finish the work, you may go out to play with Sam. (你完成工作就可以出去和Jim一起玩了。) / I wont leave until Mum comes back. (媽媽回來了我才會走。)地點狀語從句通常由 where, wherever等引導。如：Go back where you ca

6、me from! (哪里來還滾到哪里去！) / I will never forget to catch the thief who stole my necklace wherever he may be. (我永遠也不會忘記去抓住那個偷我項鏈的賊,無論他會在哪里。)原因狀語從句通常由because, since, as等引導,一般放在句首或句尾。如：He went abroad because his father had found a good university for him. (他出國了,因為他父親給他找了一所好大學。) 目的狀語從句通常由so that., so.hat.,

7、in order that. 等引導,往往放在句尾,從句中通常含有can / could / may / might等情態(tài)動詞。如：He got up earlier so that he could catch the first train. (他起身更早為的是趕上第一班車。)結果狀語從句通常由 so that., so.that. 等引導,放在句尾。結果狀語從句一般表示已經(jīng)發(fā)生的事情,故多為過去時態(tài)。如：He lost so many bikes that he decided never to buy a new one. (他丟了那么多輛自行車,他決定再也不買新車了。) 比較狀語從句

8、通常由as, than, as (so).as等引導,一般省略從句的謂語部分,只剩下名詞或代詞(用主格或賓格均可)。如：Jane is much taller than I/me. (Jane比我高多了。) / I dont have as many books as you (do). (我書沒有你多)讓步狀語從句通常由though (although), as, even if( even though), however, whatever等引導。如：Even if you pay the debt(債務) for me, I will not thank you because it

9、has nothing to do with me. (即使你替我還了債我也不會感謝你,因為它與我毫無關系。) / He wears a T-shirt though it is very cold. (他穿了一件T恤衫,盡管天很冷。)條件狀語從句通常由if, unless, as long as等引導,條件狀語從句一般放在句首或句尾,特別注意,時間狀語從句不允許使用將來時,而應該用現(xiàn)在時替代。You will certainly fail in the coming final exams unless you work much harder. (即將來到的期末考試你肯定考不及格,除非你更

10、用功。) / If it doesn t rain tomorrow, we shall go hiking. (如果明天不下雨我們就要去徒步旅行。)注意 1、because與so；(al)though與but；if與so不可以同在一個句子中成對出現(xiàn)。 2、時間、條件、原因,讓步狀語從句放在句首時需要用逗號與主句隔開。(4) 定語從句：在復合句中作定語用修飾句子中某一名詞或代詞的從句叫定語從句。 定語從句的位置：放在名詞或代詞的后面。如：The man who has an umbrella in his hand is my uncle. (手上抓了一把雨傘的人是我的叔叔。) 語法術語的改變

11、：被修飾的名詞或代詞稱為先行詞；引導定語從句的連接詞稱為關系詞,其中that、which、who稱為關系代詞,where、when、how稱為關系副詞。 關系代詞或關系副詞的作用：關系代詞who、whom 和whose指人,分別在從句中作主語、賓語和定語。which指物that多指物, 有時也指人,它們在從句中可以作主語或賓語。定語從句中關系代詞作從句賓語時可以省略。This is the thief (that/who/whom) we have been looking for these days. (這個就是我們近日一直在找的小偷。) / Please find a room whic

12、h is big enough for all of us to live in. (請找一間足夠大能住下我們全體的房間。)關系副詞when或where引導定語從句時,它們在從句中分別作時間狀語和地點狀語。如：This is the room where they had a quarrel a week ago. (這是一個星期前他們吵架的房間。) / I can never forget the day when I first saw you. (我永遠不會忘記第一次見到你的日子。) 限制性定語從句和非限制性定語從句。限制性定語從句在句中不能省略,否則主句意思就不完整。非限制性定語從句和

13、主句之間往往用逗號分開,這種從句是一種附加說明,如果從句子中省去,也不致于影響主句的意思。如：She spent the whole evening talking about her latest book, which none of us had heard of. (她一個晚上都在談論她最近的書,我們一個人都沒有聽說過那本書。)注解1、關系代詞只能用that的情況：當先行詞是指事物的不定代詞(all, anything等),或先行詞部分含有最高級,或含有序數(shù)詞時,不能用其他的關系代詞,只能用that. 如：All that Lily told me seems untrue. (Lil

14、y告訴我的話似乎不真實。) / Can you give me anything that has no sugar inside? (能不能給我點里面沒有糖的東西？) / This is the first two-story bus that runs in our city. (這是第一輛運行于我市的雙層公交車。) 2、關系代詞在從句中作主語時一般用who(指人)、that(指物),而不用that指人或用which指物。 如：Do you know the woman who is weeping in the corner? (你認識那個在角落里哭泣的女人嗎？) / Do not te

15、ll me any words that have nothing to do with me. (跟我無關的話,請一個字也不要說。)3、關系代詞作從句的賓語時,常用which或whom,較少使用that或who,而且,關系代詞常常省略。如：Toms father was the first parent whom our teacher talked to. (Tom的父親是我們老師第一個談話的人。) 4、當關系代詞緊跟在介詞后面時,必須用which或whom,而當介詞移到句尾時,則又可以使用that或who. 如：This is the room in which Miss Li once

16、 lived. (= This is the room Miss Li once lived in.) (這是李小姐曾經(jīng)居住過的房間。)(5) 主語從句：在句子中充當句子主語的從句叫主語從句。位于謂語動詞之前。通常由that,whether以及疑問連詞引導。一般情況下,常用it替代主語從句,而將主語從句移到句尾。如：When we should start is still a question. (我們該在什么時候開始還是個問題呢。) 十五、直接引語和間接引語(初中不作特別要求)1、直接引語和間接引語：在陳述句中,直接引用說話人原來的語句,稱為直接引語。在書寫時,直接引語用引號。用自己的詞語

17、來轉述表達原來說話人說的內容,稱為間接引語。2、直接引語改變?yōu)殚g接引語：1、直接引語如果是陳述句,變?yōu)殚g接引語時應注意以下各點：不用引號,而用連接詞that,但有時可省略。人稱作相應變化；主句里的動詞如果是過去時,間接引語中的時態(tài)一般應作相應改變： 一般現(xiàn)在時變一般過去時；一般將來時變過去將來時；現(xiàn)在進行時變過去進行時；現(xiàn)在完成時變成過去完成時；一般過去時變成過去完成時；但一般過去時如與一個具體的過去時間連用,則時態(tài)不變。如：He says,"I am not from the USA.”He says that he is not from the USA. Mr Smith sa

18、id to his girl friend,“ I haven t seen you for a long time.” Mr Smith said to his girl friend that he had not seen her for a long time.2、直接引語如果是一般疑問句,變?yōu)殚g接引語時,需用從屬連接詞whether或if引導,詞序要改變。如：Lin Tao said to Miss Green, "Is it made in China?” Lin Tao asked Miss Green if it was made in China. 3、直接引語如果是特殊疑問句,變?yōu)殚g接引語時,需用疑問詞引導,詞序是：連詞+主語+謂語。 如：Lucy said to me, “How can I help?” Lucy asked me how she could help.4、直接引語如是祈使句,變間接引語時,須將祈使句變?yōu)閯釉~不定式,并在動詞不定式前用tell, ask, order. 如：He said to the little boy,“ Come here, young man! ”