1、并列连接词连接并列的词、短语、从句或句子。 常见的并列连接词有:and(和),but(但是),or(或者,否则),nor(也不),so(所以),however(然而,无论如何),for(因为),still(可是),as well as(也),both. . and. . . (. . . 和. . . ),not only . . . but also. . . (不但…而且…),either… or…(或…或…),neither… nor…(既不…也不…)等。
2、从属连接词用于引导从句,常见的从属连接词有:
when(当…时候),while(正当…时候),after(在…之后),before(在…之前),since(自从),until(直到),although/though(虽然),if(假如),as(如…一样;由于),as …as…(和…一样),as far as(就…而言),as long as(只要),as soon as(一…就…),even if(即使),because(因为),unless(除非),than(比…),whether(是否…),in order that…(为了),so…that…(如此…以致),so that…(以便),now that…(遥既然),by the time…(到…时候),every time…(每当),as if…(仿佛),no matter when(或whenever)(无论何时),no matter where(或wherever)(无论在哪里)等。
[辨析]
(1)because、as、since、for的用法:because(因为)表示原因的语气遥,常表示必然的因果关系,从句一般放在主句后面;另外,回答why的问句只能用because. as(因为)表示一般的因果关系,语气比because弱,说明比较遥的原因,它引导的从句可以放在句首也可以放在句尾。 since(既然)表示对方已经知道、无需加以说明的原因或事实。 for(因为)是并列连词,语气较弱,用来补充说明理由或提供一种解释。 如:He is not at school todaybecausehe is seriously ill. (他遥没有上学因为他病得厉害)/Asall of you have got here, now, let’s go to the zoo. (既然大伙儿都到了我们就去动物园吧)/ I will ask Lin Tao to go with mesinceyou are very busy. (既然你很忙我就叫林涛和我一起去吧)/ We must be off nowforthe match starts at 7:00. (我们得走了因为遥在七点开始)
(2)if、whether的区别:表示是否时,if和whether同义,引导宾语从句,另外,whether还可以引导主语从句、表语从句(以及同位语从句)等名词遥从句或者让步状语从句;而if还可以表示如果,引导条件状语从句, (主句与从句遵循主将从现的原则)。 如:I don’t knowif/whetherhe will arrive on time. (我不知道他是不是会按时到达)/ I will ring you upifhe arrives on time. (如果他按时到达我会给你打电话的)
[注意]下列情况只能用whether不能用if:①引导主语从句,②引导表语从句,③引导从句作介词宾语,④引导不定式短语,⑤引导让步状语从句,⑥在动词discuss之后,⑦在wonder / not sure之后,⑧在if与whether含义易混时。 如:Whetherit is a fine day next Sunday is still a question. (下个星期天是不是个好天还是个问题)(引导主语从句)/ Please ask himwhetherto go there with a raincoator not. (请问一下带不带雨衣去那儿)(作动词的宾语)/ Hainan is the place to be,whether it’s summer or winter. (海南是个该去的地方无论冬夏)(引导让步状语从句)/ Please let me knowwhetheryou need my help. (请告诉我你是否需要我的帮助)(引导宾语从句)(如果换成if则还可能表示如果你需要我的帮助请告知)
(3)while、when、as的用法区别:while常表示一个较长的动作,它引导的从句动作与主句的动作是只能是同时发生的、是平行的;when可以表示较短的动作也可以表示较长的动作,主句和从句的动作可以同时发生也可以先后发生;as与上两词同义,可替换while和when, 表示主句和从句的动作同时发生,常译为一边……一边……。 如:Please do not trouble mewhileI am writing my homework. (我写作业时请不要打扰我)/ I’ll go homewhenI have finished my job. (遥完了活儿就回去)(不是同时发生)/ They were running quickly across the roadwhenthey heard the sound of a truck coming. (他们正快速地穿过马路忽然听到了卡车开来的声音)/Aswe walked in the dark street, we sang songs and talked loudly. (当我们在黑洞洞的街上走路时我们高声地唱歌说话)
(4)till/until与not…till/until的区别:前者表示一个延续遥的动作,后者表示一个才开始的动作。 如:I will stay here and watch the babyuntil you return. (我会呆在这里看着娃娃直到你回来)(stay这个动作一直进行到你return)/ They won’t go on workinguntil they get what they think is reasonable. (他们要到获得了他们认为合理的东西时才会继续干下去的)
另外till与until基本可以互换,但是在句首时只能用until,不能用till. 如:Untilthe last minute of the match we kept playing. (我们坚持到遥的较后一分钟)/ Notuntilhe had finished his work did he go home. (直到做完工作他才回家)(倒装句)
(5)though与although的区别:两个词都表示虽然,均遥以与but同时遥,但在句中可加still或yet连用。 although尽管、虽然仅作连词,比较正式,一般可以换为though;though虽然、尽管、即使,①还可以与even连用(=even if),表示即使、纵然,②作副词时意思是然而、不过,不能放在句首。 ③although不能放在句末,though则可以,用,隔开。 如:He passed the examsalthoughillness prevented him from going to classes. (尽管疾病使他无法上课但是他还是通过了考试)/ she won’t leave the TV set,even thoughher husband is waiting for her for the supper. (她不愿离开电视机虽然丈夫在等她吃饭)/ It was a quiet party. I had a good time,though. (这是个不热闹的聚会尽管如此我还是玩得很开心)
1. I had to go to work by taxi_______ I got up late this morning.
A. so B. but C. and D. because 用and, but, so填空:Jane didn’t work hard last term, _______ she failed many subjects. I like playing badminton, _______ my sister doesn’t. David got up early this morning, _______ he got to school on time. Lucy bought a book on animals, _______ she liked it very much.