Adverbial Clauses条件状语条件状语条件状语条件状语原因状语原因状语原因状语原因状语目的状语目的状语目的状语目的状语地点状语地点状语地点状语地点状语比较状语比较状语比较状语比较状语结果状语结果状语结果状语结果状语时间状语时间状语时间状语时间状语让步状语让步状语让步状语让步状语方式状语方式状语方式状语方式状语掌握状语从句的关键1.准确掌握每一个连词的含义。2.注意主句和从句的时态呼应。(1) as , while , whenWhich do you choose?Im going to the post office._ you are there, can you buy me some stamps?AAs Bwhile CBecause DIf 连接词类别作 用例 句asas 表示“当的时候”，往往和 when/ while 通用，但它着重强调主句与从句的动作或事情同时或几乎同时发生。1.She came up as I was cooking.（同时）2.The runners started as the gun went off.（几乎同时）whenwhen可以和延续性动词连用，也可以和短暂性动词连用；when从句的谓语动词可以在主句谓语动作之前、之后或同时发生；while和as从句的谓语动作必须是和主句谓语动作同时发生。 1.When we were at school, we went to the library every day.（在一段时间内）2.Sorry，I was out when you called me（call为短暂性动词）对不起，你打电话时我刚好外出了。 3. When I got to the airport，the guests had left（got to后发生）当我赶到飞机场时，客人们已经离开了。 while从句动作和主句动作同时发生，且从句动作为延续性动词时，(when，while，as都可使用)。 主句中的动作或事情是在从句中的动作或事情的进展过程中发生，从句中的动词一般要用延续性动词。1.When While As we were dancing，a stranger came in（dance为延续性动词）。2.Please dont talk so loud while others are working. While ,when 在句中的不同含义:While I was walking down the street, I came across an old friend. ( while=_)While I really dont like art, I find his work impressive. ( while =_ )He likes pop music, while I am fond of folk music. Strike while iron is hot.1)They were walking down the street when they saw an accident.2) I had just got home when it began to rain.3) I was about to go swimming when our guide stopped me.4) Its cold when it snows. 1.As I left the house, I forgot the key.2. As I get older, I get more optimistic.3. He looked behind as he went.4. As the weather is so bad, we have to stay home.5. You can do it as you like.6. Old as he is, he is still energetic.Judge the meanings of “as”.Fill in the blanks with “when, while, as”1_ you meet a word you dont know, consult the dictionary.2.The students took notes _ they listened. 3._ the wind rose ,the noise increased. 4.She called _ I was out. 5.We must strike _ the iron is hot. 6._you have finished your work, you may have a rest. 7. I was just reading a book _ she came into my room. whenasAswhilewhileWhenwhenbefore用法1.We had sailed four days and four nights before we saw land.2. We hadnt run a mile before he felt tired.3. Please write it down before you forget it.4. Before I could get in a word, he had measured me. 注意：before从句中谓语不用否定式。Before they reached the station, the train had gone. 才还没有/不到就 趁（还未）还没来得及 含有before的句型结构：1. It will be / was一段时间before“过多久才” It_(还要过两年)he leaves the country.It _(过了很长一段时间) before he got to sleep again.2. It will be / was + not一段时间before “不多久就”It wasnt two years before he left the country. It was not long before he came back.Since用法1.I have returned home four times since I came here.2. She has been working here (ever since) he left school.常用句型：常用句型：It has been (is) + 时间段时间段 + since从句从句 “自从自从有多长时间了有多长时间了 ”毕业已经有六年时间了。It has been (is) six years since she graduated from the university. （2）引导时间状语从句的连接词除上述外还有： till, until, Dont get off the bus until it has stopped.He waited for his father until (till) it was twelve oclock. once, as soon as, directly, immediately, As soon as I have finished it , Ill give you a call.Once you show any fear, he will attack you. He made for the door directly he heard the knock. the moment, the minute ,the second 一就hardly / scarcely when, no sooner than表示“一就We had hardly got into the country when it began to rain. He had no sooner arrived than she started complaining. each time, every time, the first time, by the timeEach time he came to my city, he would call on me.The first time I came to Shanghai, I loved it very much.By the time the doctor arrived ,the man had come to.连接词：because, as, since, now that, for,e.g. He didnt come to school because he was ill.表示“直接”原因。c.f. He might be ill, for he didnt come to school.表示“间接的推断”原因.不可出现在句首。because直接原因，非推断语气最强 回答why的问题。since 通常放句首译为“既然”= now thatas不谈自明的原因，语气最弱。for放句中，引导后半句表原因, 或补充推断的理由。Back to school课后作业