第四讲状语从句时间和条件状语从句全析考法.单句语法填空 1(2018北京高考改编)_ we dont stop climate change, many animals and plants in the world will be gone.解析：If句意：如果我们不阻止气候变化，世界上的许多动植物将会消失。根据句意可知，此处应该用 if 引导条件状语从句，表示主句内容发生的条件。2(2016全国卷)Over time, _ the population grew, people began cutting food into small pieces so it would cook more quickly. 解析： as/when句意：慢慢地，随着人口的增加(或：当人口增加时)，为了使食物熟得更快，人们开始把食物切成小块。根据句意可知，此处可用as/when引导时间状语从句。3(2016四川高考)The mother held the baby in her front paws much the way a human does._ it cried, she rocked it back and forth and gave it little comforting pats.解析： When/If第二句句意：当它哭的时候/如果它哭了，熊猫妈妈会来回摇晃它，轻轻拍打，给它安慰。根据句意可知，应填when或if。4(2014辽宁高考)Unbelievable! Oh .，_ you dont mind, Ill stop and take a deep breath.解析：if此处表示：噢如果你不介意，我要停下来做一下深呼吸。根据句意可知，应填if引导条件状语从句。.单句改错1(2018全国卷)The games my parents taught me where I was a child turned out to be very useful later in my life._解析：wherewhen根据句意可知，父母是在我小时候教我玩纸牌的，所以此处要用when引导时间状语从句。2(2015陕西高考)My only mistake was that I dropped some on the floor after I was packing them up. _解析： afterwhen/while句意：我所犯的唯一的错误就是当我打包它们(饼干)的时候，掉在了地上一些。when/while“当的时候”，after“在之后”。根据句意应将after改为when/while。谨记规则(一)时间状语从句1when, while和as引导的时间状语从句连词含义用法when当时候可与延续性动词或非延续性动词连用；从句动作可以发生在主句动作之前、之后或与主句动作同时发生while当时候只可与延续性动词连用；侧重于主句动作与从句动作相对比as一边一边；随着常与延续性动词连用；从句动作与主句动作同时或几乎同时发生Researchers in Britain found that when French music was played, sales of French wines went up.英国的研究者发现，播放法国音乐时，法国葡萄酒的销量会增加。While watching TV, children do not merely absorb words and images.孩子们在看电视的时候，接收的不只是文字和图像信息。As he grew older, he became less active.随着他逐渐长大，他变得不那么活泼了。特别注意如果主句表示的是非延续性动作，而从句用延续性动词的进行时态表示在一段时间内正在进行的动作，则when, while与as可互换使用。When/While/As I was walking down the street, I came across an old friend.我正沿着大街走时，碰巧遇到了我的一个老朋友。2表示“一就”含义的词或短语引导的时间状语从句(1)有的名词(短语)或副词可引导时间状语从句，如：the moment, the minute, the second, the instant, immediately, directly, instantly等，另外as soon as也可引导时间状语从句，从句中用一般时态代替将来时态。For example, the moment you get on the airplane, start adjusting your biological clock to the destinations time.例如，你一上飞机，就开始按照目的地的时间调整你的生物钟。The boy ran off the minute he saw the owner of the orchard.那个男孩一见到果园的主人就跑开了。(2)在hardly/scarcely . when/before .和no sooner . than .结构中，主句用过去完成时，than, before或when所在的从句用一般过去时。I had hardly told him the news when he stopped listening.我一告诉他那则消息他就不听了。He had no sooner finished his speech than the students started cheering.他一完成演讲，学生就开始欢呼起来。特别注意在hardly/scarcely . when/before ., no sooner . than .结构中，当hardly, scarcely或no sooner位于句首时，主句要用部分倒装。They had hardly reached Edinburgh when they were ordered to return to London.Hardly had they reached Edinburgh when they were ordered to return to London.他们刚抵达爱丁堡就接到了回伦敦的命令。3till, until和not . until/till的用法until, till两者均表示“直到为止”，引导时间状语从句。肯定句中，其主句谓语动词必须为延续性动词，表示某动作一直延续到某时间为止。not . until ., not . till .两者均表示“直到才”，not所在的主句的谓语动词必须为非延续性动词，表示某动作直到某时间才开始。until可用于句首，而till不可放在句首，till一般不用于强调句型。The father waited until his daughter had finished her homework.那位父亲一直等到他的女儿做完家庭作业。The baby didnt go to bed until/till his mother returned.这个婴儿直到他的妈妈回来才睡觉。4after, before引导的时间状语从句after表示“在之后”，before表示“在之前；还没来得及就”。He changed his name after he left his hometown.离开家乡后他把名字改了。Before modern medicine changed the laws of nature, many children died of common childhood diseases.在现代医学改变自然规律之前，许多孩子死于一些常见的儿童疾病。特别注意(1)“It will be/was时间段before从句”表示“在之前还要多久/过了多久才”。It will be half a year before I graduate.半年后我才毕业。(2)“It wont be/wasnt时间段before从句”表示“过不了多久就/没过多久就”。It wasnt long before we started.没过多久我们就动身了。5since引导的时间状语从句since意为“自从以来”，从句的谓语动词一般是非延续性动词，主句的谓语动词一般是延续性动词。since从句的时态若是一般过去时，主句常用现在完成时或现在完成进行时。此外，since常用于以下句型：It is/has been时间段since从句(常用一般过去时)“It is/has been时间段since从句(常用一般过去时)”句型的含义取决于从句的谓语动词是否为延续性动词。若从句谓语动词为非延续性动词，则表示从该动作开始一直延续到现在多久；若从句谓语动词为延续性动词，则表示从该动作结束到现在多久。They have been friends since they met for the first time in London.自从在伦敦第一次见面以来，他们一直是朋友。It is three years since the war ended.战争已经结束三年了。It is three years since he lived here.他不在这里住已经有三年了。6其他常见名词短语引导的时间状语从句every time 每次each time 每次any time 任何时候 next time 下次all the time (在某段时间内)一直the first/last time 一次/最后一次the day/year . 天/年Every time I meet her I always forget her name.每次我见到她时，我总记不起她的名字。The first time I met her, I thought her nice and honest.我第一次遇见她时，就觉得她友好又诚实。(二)条件状语从句1引导条件状语从句的常见从属连词(短语)有：if, unless, as/so long as, in case (万一), once, on condition that, provided/providing (that), supposing/suppose (that), assuming that (假设)等。Youll fail the exam unless you study hard.除非你努力学习，否则你会考试不及格。They agreed to lend us the car on condition that we returned it before the weekend.他们同意把车借给我们，条件是我们必须在周末前归还。My parents dont mind what job I do as long as I am happy.我的