连词
1.并列连词.
①both … and,either … or,neither … nor
both … and“双方都”,连接句子的两个主语时,其后谓语动词通常用使用复数形式.either … or与neither … nor注意采取“就近原则”.
②not only … but also,as well as
注意：两者强调对象不同,not only … but also强调的是but also之后部分,而as well as则强调其前面的部分.not only … but also采取“就近原则”,而as well as只是一个插入语,采取“就远原则”.如：
Mr.Smith,as well as his wife and children,has come to Nanjing for a visit.
not only … but also结构中的not only可用于句首,连接两个分句时,第一个从句主谓要倒装.
Not only is he clever ,but also he is hard working.
2.从属连词.
①when、while、as都表示“当……时候”,when引导的从句的动作与主句的动词可同时发生,也可先后发生；
as、while引导的从句则强调主句和从句的动作同时发生.如：
When I go to the station,the train had already left.
He sang merrily as he was working.
②till、until均表示“到……时候止”,肯定句中的谓语必须是延续性动作.如：I worked till late at
night.若主句谓语是终止性动词,则主句要用否定形式,意为动作“到……才……”开始发生.如：
She didn’t get up until her mother came in.
注意：till和until通常情况下可以互换,只是在句首时until比till更常用.
③though、although均引导让步状语从句,意为“虽然……”,although较正式,though最常用.如：
Thouth (Although)he was tired,he kept on working.
注意：though、although引导的从句不能与but、however连用,但可以与yet、still连用.though还可以与别的词结合使用,如even though、
as though,而although则不能这样搭配.
④no sooner … than、hardly … when、as soon as三者都表示“一……就”,“刚刚……就”的意思.（A）as soon as 置于主句前后都可以,而且有备各种时态.如：As soon as she gets here I’ll tell her about
it.Mary left as soon as the finished the work.(B)hardly … when、no sooner … than不能表示将来的事,其主句的谓语动词一般用过去完成时,从句用过去时.若将hardly或no sooner放在句首,句子要倒装.如：No
sooner had he arrived than he went away again.
⑤某些表示时间的名词（词组）也可用作从属连词.它们是：the moment,the minute,the instant,the day,the time,the first(second,third …)time,the spring (summer,autumn,winter),every(each,next,
any) time(day),by the time,都可引导时间状语从句.如：
His mother died the spring he returned.
Call me up the minute he arrives.
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