状语从句引导状语从句的从属连词：（包括：时间，地点，原因，条件，让步，结果，目的，方式，比较等）1时间状语从句：A. *when: 从句可用1)非延续性动词，表点时间=at the time when…2)延续性动词，表段时间，此时可与while / as互换。
注：a)从句中的动作既可与主句动作同时发生b)也可在主句动作之前或之后发生。
后者不可与while/as 两者换用。
.When I got home, he was having supper. b).When(=Before) I got to the party , some guests had left.When(=After)he finished his work, he took a short rest.3）也可做并列连词，“这时”be about to do/ be going to do/ be doing… when…had hardly/just/scarcely/not done…when…*while:1）“在…期间”；从句只能用延续性动词，表段时间=during the time when...2）当“趁着”讲。
3) “尽管” = althougheg.____ I admit that the problems are difficult, I don’t agree that they can’t be solved.A. WhileB. WhenC. AsD. Because3）也可做并列连词，表对比关系，“而”。
*as: 1）“随着”，指动作的进程(with也有“随着”之意，但是介词，只跟短语。
)“一边```一边```”，强调主从句谓动的同时发生。
1._______________he was in Beijing, he made a lot of friends.--->When /While in Beijing,…2._______________he was studying in Beijing, he made a lot of friends.--->When /While studying in Beijing,…--->During the time when he was( studying) in Beijing,…3.______he arrived in Beijing, he received a warm welcome.--->At the time(when )he arrived in Beijing,…/At the time of his arrival, …4. _____ time goes on, the situation is getting worse and worse.5. The atmosphere gets thinner and thinner______ the height increases. (从句)--->with the increase of the height. （短语）6. The students took notes ______they listened./ He hurried home, looking behind _____ he went.7. Strike __________the iron is white-hot. 趁热打铁。
8. Come and pay a visit to the park_______ all the flowers are in blossom. 趁着花还开着，去公园玩一趟吧。
9. I had hardly / scarcely closed my eyes ________ someone knocked at the door.-->I had no sooner closed my eyes ________ ……10. The Chinese prefers drinking tea ___________ Americans like drinking coffee.B. before/after:1.She had studied Russian for three years ________she was sent to the Soviet Union.---> ________being sent to the Soviet Union.21).It won’t be long ________ we meet again.2). They hadn’t known each other long ________ they got married.3. It seemed only seconds ______ the boy finished washing his face. 4)we hadn’t waited long ____the bus came.5). How time flies! Two and a half years have passed _______ we know it.以上的before一律译成“就”3. I’m afraid it will be 3 years ______ we meet again. 2). I must finish the composition _____ I go home.此处译为“才”4. __________ it was made into a movie, the novel became even more popular.-->_________ being made into a movie, …-->_________been made into a movie, …5. Three billion years _________ life began, the earth is now the home to many different kinds of living things.6. Karaoke was spread to the whole world shortly / soon ________ it was invented.C. as soon as /oncethe moment / the instant / the minuteimmediately /instantly /directly1). The moment I saw him, I knew he was a warm-hearted man.2). As soon as the film star appeared on the stage, there arose a wild slap.3). The moment he entered the room, he fixed the chain across the door.---> ______ entering the room, he…4). Immediately she heard the noise, she rushed into the room.---> ______ hearing the noise ,she …D. till / until1).I knew nothing about it _______/_______ he told me. BUT:__________ he told me, I knew nothing about it.2).She stood (延续性动词用肯定式) there _____ they had passed out of sight. 她一直站到他们从视野中消失了为止。
3).She didn’t leave/ go away (非延续性动词用否定式)there_______ they had passed …她直到他们看不见了才离开。
几组延续/ not+非延续性动词的比较：wait / not leave stay here /not go away sit/not stand up lie/ not get up stand/ not sit work / not stop working go on working/ not finish4).Until we have thought it over , we’ll take ______ steps. A. no B. any C. some D. all5)将3）改成强调句式：改成倒装句式：6).---When will the concert begin? ---__________.A. Till 7:30 B. Not until 7:30 C. Not after 7:30 D. From 7:30[]在强调结构中或与not连用时，多用until.[][] 时间状语从句可以缩略，常见形式：1. Don’t speak until _________(speak) to.2. Once _______ (see ),it can never be forgotten.3. He was a swimmer when a child /as a child.4. Relax yourself whenever possible.5. He often makes mistakes when ___________(speak) English. []分词代替从句时，主从句的主语必须一致。
6. He failed to express himself when ____________(introduce) to the girl.E. since:自从```以来从句多用一般过去时，主句多用完成式或完成进行式；但若表达“时间过了多久”则用“It is + 时间段”。
Much change has taken place_______ the Gang of Four was knocked down.It is over 75 years _________ the Long March ended in victory in 1935.1).-What was the party like? -- Wonderful. It’s years _______ I enjoyed myself so much last time.A. afterB. whenC. beforeD. since2)---How long has the bank been in business? ---_________ 1987. A. After B. In C. From D. Since3)_________ have you known him? A. Since how long B. Since when C. Since long ago D. Since when was it(答案：B. Since when = Since how long ago。