必修2重点语法汇总Unit4will和be going to用法区别：1.will的用法（will是情态动词，后接动词原形。
常表示依据直觉、知识、经验等做出的揣测）①will表将来存在的状态、将要发生的动作或将来的经常性、习惯性动作，常与时间状语next week, tomorrow等连用。
例：They will be doctors 5 years later. 五年后，他们将成为医生。
Each time he comes to the city on business, he will visit his English teacher.每次来这个城市出差，他都会拜访他的英语老师。
I will go to Britain next week. 下星期我要去英国。
②事物固有的属性、特征或发展的必然趋势。
例：It will become warm when spring comes. 当春天来临时，天气将变暖。
Fish will die without water. 鱼儿离开水会死。
③说话时临时做出的决定。
—I hear Jim was injured in a car accident. He is in hospital now.听说吉姆在一场交通事故中受伤了，现在在医院。
—Then I will go to see him. 那我这就去看他。
④表示请求和邀请，常用于第二人称。
Will you come in and have a drink? 你愿意进来喝一杯吗？⑤说话者对未来作出语言和揣测。
You will be all right after taking this medicine. 吃过这药你就会好了。
⑥可以表意愿、意图、自愿或坚持做某事。
He’ll take you home. You only have to ask. 他愿意送你回家，你只要跟他说一声就行。
be going to的用法（打算，将要…）①事先经过考虑或准备，打算最近或将来要做的事。
What are you going to be when you grow up? 等你长大，你想要成为什么？②根据现在的迹象，预计要发生的事。
The old man is so weak, he is going to die. 老人如此虚弱，他活不长了。
will与be going to表将来时的区别①be going to可用于表将来时的条件状语从句中，而will不行。
错误：If you will play basketball, you have to finish your homework first.正确：If you are going to play basket, you have to finish your homework first.②will可以用在带有条件状语从句的主句中表将来，而be going to不行。
错误：If it is fine, we are going to go camping.正确：If it is fine, we will go camping.③be going to表示近期、眼下就要发生的事情，will表示的将来时间则更远一些。
He is going to writhe a letter tonight. 他打算今晚写封信。
He will write a book one day. 他打算将来写本书。
④will临时决定要做的事，be going to事先考虑要做的事。
—Why are you taking it out? 干嘛要把它拿出来？—I’m going to wash it. 我想把它洗一洗。
—Where is the telephone book? 电话簿在哪里？—I’ll get it for you. 我去给你拿。
虚拟语气if条件句中的虚拟语气①与现在事实相反的虚拟语气：条件句谓语用“过去时（be动词一般用were）”，主句谓语用“would/should/could/might+动词原形”。
If I saw him now, I would be very happy. 如果我现在见到他，我会很高兴的。
②与过去事实相反的虚拟语气：条件句谓语用“过去完成时”，主句谓语用“would/should/could/might+ have+过去分词”。
If he had followed my advice, he wouldn’t have lost his job.如果他当时接受我的建议，就不会丢掉他的工作了。
③与将来事实相反的虚拟语气：条件句谓语用“过去时或should/were to+动词原形”，主句谓语用“would/should/could/might+ 动词原形”。
If it snowed/were to snow/should snow tomorrow, we would take photos. 如果明天下雪，我们就照相。
④混合虚拟语气：主句和虚拟条件从句的动作发生时间不一致，此时，主句和从句的谓语动词要根据所指的不同时间选择各自适当的形式。
If he hadn’t hurt his leg in the last training, he would join in the coming World Cup, which he has been longing to compete in. 要是在上次训练中他的腿没受伤的话，他会参加他渴望已久的世界杯。
⑤含蓄虚拟语气：有时为了表达的需要，假设的情况并不以if条件句表现出来，而是通过but for, without, otherwise, or等介词、副词暗含在上下文中。
But for your help, it would have caused a serious loss. 要不是你的帮助，将会导致巨大损失。
⑥若条件从句中有were, had, should，可把if省略，把were, had, should放在主句前，形成倒装。
Had you taken my advice, you wouldn’t have failed in the examination. 如果你听了我打建议，你就不会考试不及格了。
其他从句中的虚拟语气①在名词性从句中，表示命令，建议，要求等一类动词后面的宾语从句中用虚拟语气。
即一坚持insist；二命令order, command；三建议suggest, propose, advise；五要求require, request, demand, desire, urge + that+主语+(should) do。
He insisted that he (should) be sent here. 他坚持他应该被派去那里。
suggestion, proposal, idea, plan, order, advice等名词的标语从句，同位语从句要用虚拟语气。
②wish后面所跟的宾语从句的虚拟语气对现在事实的虚拟：wish + 主语+动词过去式或wereI wish I knew where he lives. 我要是知道他住在什么地方就好了。
对过去事实的虚拟：wish + 主语+ had + 过去分词This watch has gone wrong, I wish I had bought a better make.这只表坏了，我真希望我买的是好点的牌子。
对将来事实的虚拟：wish + 主语+ would + 动词原形I wish you wouldn’t leave your clothes all over the floor. 我真希望你不把衣服丢的满地都是。
③would rather的虚拟语气，表示“宁愿，但愿”。
I’d rather you set out earlier tomorrow morning. 我宁愿你明天早晨早点出发。
④It is (high/about) time (that) …的虚拟语气It’s high time that you went to bed. 该是你睡觉的时间了。
⑤if only引导的虚拟语气，表示愿望。
If only I had another chance. 要是我再有一次机会就好了。
⑥as if从句，看语境是否与事实相反而选择是否使用虚拟语气.She talked it again and again as if she would never end. 她反复谈论那件事，好像永远也谈不完。
Unit5在复合句中修饰主句或主句中的某一部分作状语的从句叫状语从句。
状语从句通常由从属连词或起连词作用的词组引导。
状语从句根据它表达的意思不同，可分为时间、地点、原因、目的、结果、条件、方式、比较、让步九类。
时间状语从句：主要由when, whenever, after, before, as, (ever)since, as soon as, (not) until, while,immediately, the moment等连词引导。
when, while, as（当…时）的用法区别①当主句谓语动词表示短暂动作，从句中的谓语动词有持续性特征时，这三者可以互换。
例：I got the news on the radio when/while as/ I was having breakfast.②当主，从句的谓语动词都表示非持续性动作，而且两个动作几乎同时发生时，不用while, 可用when和as。
例：I met as/when I was getting off the bus.③当从句的动作发生在主句的动作之前，只能用when引导从句，不可用as或while。
例：When you have finished your work, you may have a rest.④当主句谓语动词是be doing/be about to do/had done时只能用when, when在此时相当于and at that moment就在那时。
例：They were watching the World Cup when suddenly the lights went out.⑤当主、从句的动作同时发生时，或表示对比关系，用while。
例：She thought I was talking about her daughter, while in fact, I was talking about my daughter.⑥as表示“随着”例：As time goes on, it’s getting warmer and warmer.1.表示“一…就…”的结构Hardly/scarcely…when, no sooner…than和as soon as例：I had hardly/scarcely got home, when it began to rain.I had no sooner got home than it began to rain.As soon as I got home, it began to rain.注意：如果hardly, scarcely或no sooner置于句首，句子必须用倒装结构。