状语从句 （一）状语从句概述 定义状语从句用作状语，是起副词作用的句子。 位置状语从句可以放在主句之前， 也可以放在主句之后， 时间、 条件、 原因和让步状语从句放在句首时需要用逗号和主句隔开。 分类根据其作用可以分为时间、地点、原因、条件、目的、让步、 方式和比较等状语从句。 作用它可以修饰谓语、非谓语动词、定语、状语和整个句子。 （二）状语从句详解（二）状语从句详解 1. 时间状语从句时间状语从句 引导词用法示例 when意为 “当的时候” 。 When 引导从句的谓语动词可以 是延续性动词，也可以是 瞬间动词。并且 when 有 时表示“就在那时” A liar is not believed when he speaks the truth.说谎者讲真话 时也没有人相信。 When he arrives, Ill call you. When you laugh and smile, your body relaxes. while意为“在的时候，在 的同时” 。While 引导从句 的谓语动词必须是延续性 的，发生时间较长，并强 调主句和从句的动作同时 发生 （或者相对应） 。 While 有时还可以表示对比。 While I was standing at the window, I saw several boys running along the street. While John was watching TV, his wife was cooking. as意为 “一边一边” 。 AsThe writer was angry as he was 引导的动作是延续性的， 发生时间较短，一般用于 主句和从句动作同时发 生；as 也可以强调一前一 后。 travelling on a train to London because someone had invaded his “space”. He smiled as he stood up. after意为“在之后” 。表示主 句动作发生在从句动作之 后。主句与从句的动作时 间关系与 before 引导的从 句相反。 With many hungry visitors waiting, dont stay too long at your table after you have finished. If an early exit is necessary, you can leave after a scene is over. before意为“在之前” 。引导的 从句不用否定形式的谓 语，并且当 before 引导的 从句位于主句之后，有时 译成“就，才” 。当主句用 将来时，从句总是用现在 时；如果 before 引导的从 句谓语用的是过去时，则 主句动词多用过去完成 时，这样以便体现动作的 先后。 You cant watch TV before you finish your homework. Before it ended, the theatre was almost empty. My father had left for Canada just before the letter arrived. till意为“直到” 。一般情况下 可以和 until 互换。 如果主 句中的谓语动词是瞬时动 词时，必须用否定形式； 如果主句中的谓语动词是 延续性动词时，用肯定和 She didnt even know that it was an earthquake till she saw a shaking ( moving from side to side) light. The fireman worked very hard till the fire was out. 否定形式都可以，但表达 的意思不同。 until意为“直到” 。在强调句型 中多用 until。如果主句中 的谓语动词是瞬时动词 时，必须用否定形式；如 果主句中的谓语动词是延 续性动词时，用肯定和否 定形式都可以，但表达的 意思不同。 Im waiting for my sister. I wont go to see my uncle until she comes. Wait until I finish what I am doing. since意为“自从，从以来” 。 引导从句的谓语动词可以 是延续性的动词，也可以 是瞬时动词。 一般情况下， 从句谓语动词用一般过去 时，而主句的谓语动词用 现在完成时。 但在 It is +时 间+since 从句的句型中， 主句多用一般现在时。 I have been studying hard since I entered the high school. It is four years since my sister lived in Beijing. It is five years months since our boss was not in Beijing. as soon as意为“一就” 。引导时 间状语从句时，如果主句 用了将来时，从句一般使 用现在时。 Tom will call me as soon as he gets home. I will call you as soon as I arrive. 2.地点状语从句地点状语从句 引导词用法示例 where意为“哪里” 。 “where 引导 的地点状语从句， （there+） 主句” “哪里哪里就” 。 Where there is a will, there is a way. They were good persons. 主句在从句后面时， there 可 用可不用；主句在从句的前 面时，一般都不用 there. Where they went, there they were warmly welcomed. You should have put the book where you found it. wherever意 为 “ 无 论 何 地 ”。 anywhere/wherever 引 导 地 点状语从句+主句。 anywhere 本身是个副词，但是常可以 引导从句，相当于连词，意 思相当于wherever, anywhere 引导的从句可位 于主句之前，也可以位于主 句之后。 而 wherever 本身就 是个连词，表示“在何处， 无论何处” 。 Wherever the sea is, you will find seaman. Ill go anywhere you go. 3.条件状语从句条件状语从句 引导词用法示例 if连词， 意为 “假如， 如果” 。 当主句是将来时的时候， 从句要用一般现在时。 Dont talk loudly at the meeting. If you do, you will have to leave. Well go for a picnic if it doesnt rain this weekend. unless连词，意为“除非（=if not） 。当主句是将来时的 时候，从句要用一般现在 时。 Dont discuss the problems with your partner unless you are asked to do so. I wont go there unless you come with me. 4.原因状语从句原因状语从句 引导词用法示例 as意为 “因为” 。 引导原因状 语从句时表示附带。说明 “双方已知的原因” ， 语气 比 since 弱，较为正式， 位置较为灵活（常放于主 句之前） 。 As the weather is cold, I stay at home. As it is raining, youd better take a taxi. As you are tired, youd better rest. since意为 “因为” 。 引导的原因 状语从句一般放于主句之 前表示已知的、显然的理 由（通常被翻译成“既 然” ） ，较为正式，语气比 because 弱。 Since the earth looks like a ball, the sun can shine on only half of it at a time. Since the race is in April, I had to run throughout the winter, and in Boston, winters are cold. Since everybody is here. Lets begin our meeting. because意为 “因为” 。 引导的原因 状语从句一般放于主句之 后，表述直接原因，语气 较强，最适合 why 引导的 疑问句。Because 引导的 原因状语从句有时可以与 because of 短语互换。 The woman prefers winter because she can skate. Id like to collect stamps because they are interesting. Im very tired these days because of studying physics. He cant come because he is ill. = He cant come because of his illness. for意为 “因为” 。 引导的原因 状语从句并不说明主句行 为发生的直接原因，只提 供一些辅助性的补充说 He must be ill, for he is absent today. He could not have seen me, for 明， for 引导的原因状语从 句只能放于主句之后，并 且必须用逗号将其与主句 隔开。 I was not there. 5.目的状语从句目的状语从句 引导词用法示例 so that意为“以至，以便” 。目 的状语的谓语常含有 may, might, can, could, should, would 等情态动词。 Try to speak loud enough so that people can hear you clearly. Mr. Green speaks very loudly so that all the people can hear him clearly. in order that 意为“为了” ，相当于 so that. in order to 后面可以 跟动词原形构成目的状 语，不是目的状语从句。 We shall let you know the details soon in order that you can/may make a arrangements. 6.结果状语从句结果状语从句 引导词用法示例 sothat意为“如此以至于”。 so+ adj./adv.原级+that, so是 副词， 只能修饰形容词和副 词。 so 还可与表示数量的形 容 词many, few, much, little(这四个形容词表示多 或少时)连用,形成固定搭 配。so+ many 或 few+复数 可数名词+that; so+ much 或 little+不可数名词+that. This year it has rained so heavily in South China that lots of problems are caused. The ice on the lake wa