2023年初中英语语法精讲之状语从句

2023年初中英语语法精讲之状语从句 　　状语从句的概念： 　　状语从句指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。状语从句一般由连词(从属连词)引导，也可以由词组引起。从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。 　　比较while/as/when： 　　1、as/when引导短暂性动作的动词例句： 　　如：Just as/Just when/When I stopped my car, a man came up to me. 　　2、当从句的动作发生于主句动作之前，只能用when引导这个从句，不可用as或while。 　　如：When you have finished your work, you may have a rest. 　　3、从句表示“随时间推移”连词能用as，不用when或while。 　　如：As the day went on, the weather got worse. 　　比较untill/till： 　　两个连词意义相同,肯定形式表示的意思是“做某事直至某时”，动词必须是延续性的。否定形式表达的意思是“直至某时才做某事”，动词为延续性或非延续性都可以。 　　正确使用这两个连词的关键之一就在于判断句中的动词该用肯定式还是否定式。 　　肯定句例句：I slept until midnight. 我一直睡到半夜时醒了。 　　Wait till I call you. 等着我叫你。 　　注意：在肯定句中可用before代替：Let's get in the wheat before the sunsets. 　　否定句例句：She didn't arrive until 6o'clock. 　　I didn't manage to do it until you had explained how. 　　1、Until可用于句首，而till通常不用于句首。 　　例句：Until you told me, I had heard nothing of what happened. 　　2、Untilwhen疑问句中，until要放在句首。 　　例句：Until when are you staying 你呆到什么时候？ 　　注意：否定句可用另外两种句式表示。 　　1）Not until…在句首，主句用倒装。 　　例句：Not until the early years of the19th century did man know what heat is. 　　2）It is not until…that… 　　状语从句的用种类： 　　1、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, everytime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. 　　2、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, nowthat（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. 　　3、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. 　　4、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. 　　5、结果状语从句： 　　结果状语从句是表示 ... ...