由从句担任的状语，在句子中可修饰谓语（或其它动词）、形容词、副词或是整个句子，它可以用来表示时间、地点、原因、目的、结果、条件、方式、比较、让步等。状语从句是一较大的语法项目，也是近几年高考题中常见的一个重要试点。高考中已考查了时间、让步、地点、条件、目的等状语从句，这些从句仍是今后高考热点，应作充分准备。同时对方式状语从句也应引起重视。

　　（一）时间状语从句

　　表示时间的状语从句可由when, as, while, whenever, after, before, till (until), since, once, as soon as (或the moment ), by the time, no sooner … than, hardly (scarcely) … when, every time等引导。

　　e.g. When I came into the office, the teachers were having a meeting.

　　 He started as soon as he received the news.

　　 Once you see him, you will never forget him.

　　 No sooner had I gone to bed than I went to sleep.

　　（二）原因状语从句

　　 原因状语从句是表示原因或理由的，引导这类从句的最常用的连词是because, since, as , now that（既然）等，for 表示因果关系时（它引导的不是从句）为并列连词，语气不如because强。

　　 e.g. He is disappointed because he didn't get the position.

　　 As it is raining, I will not go out.

　　 Now that you mention it, I do remember.

　　（三）地点状语从句

　　引导地点状语从句的连词是where 和wherever等。

　　e.g. Sit wherever you like.

　　 Make a mark where you have a question.

　　（四）目的状语从句

　　引导目的状语从句最常用的词（组）是so, so that（从句谓语常有情态动词）, in order that, in case（以防，以免）等。

　　e.g. Speak clearly, so that they may understand you.

　　 She has bought the book in order that she could follow the TV lessons.

　　 He left early in case he should miss the train.

　　（五）结果状语从句

　　 结果状语从句是表示事态结果的从句，通常主句是原因，从句是结果。由so that （从句谓语一般没有情态动词）, so … that, such … that等引导。

　　 e.g. She was ill, so that she didn't attend the meeting.

　　 He was so excited that he could not say a word.

　　 She is such a good teacher that everyone admires her.

　　（六）条件状语从句

　　 条件状语从句分真实性（有可能实现的事情）与非真实性（条件与事实相反或者在说话者看来不大可能实现的事情）条件句。引导条件状语从句的词（组）主要有if, unless, so (as) long as, on condition that, so (as) far as, if only ( = if )。注意：条件从句中的if 不能用whether替换。

　　 e.g. If he is not in the office, he must be out for lunch.

 

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