我们首先来看看虚拟语气的基本用法
首先，虚拟语气用于说话人表达并不是事实的情况，作用是表达假设、愿望、怀疑和推测。如果你想说的是以上四种情况之一，就需要用到虚拟语气。通常情况下虚拟语气是建立在一个假设的条件之上，既 if 引导的条件状语，当然这个条件不是事实。而假设的时态不同，虚拟语气的结构也不同。注：红圈位置的be动词只能用were，不管主语是谁。英文：If I brought the book now, I would give you.英文：If I had found that book yesterday, I should have given you.英文：If I should find the book（If I were to find the book / If I found the book）tomorrow, I would give it to you.If you had met me a bit earlier, you should have passed the IELTS.如果每一个人都只知道相互竞争而不合作，这个社会就会混乱。If people only competed with each other, carrying out no cooperation at all, there would be great chaos in our society.ps. 假设条件很适合在讨论社会问题的大作文中使用，也可以用于口语中一件你想做没有做的，后悔的事，以及表达推测和未实现的愿望。比如：如果我刚才就听从你的建议，现在就不会陷入麻烦。这里的条件是对过去的虚拟，而主句则是现在的虚拟。这种情况下，就要根据上面的表格进行搭配。英文: If I had followed your advice just now, I would not be in trouble.在从句中，were，had，should可以倒装到句首，这时if必须省略掉，而且否定词not不能放到前面去。If I had found that book yesterday, I should have given you.Had I found that book......If I had not seen him then, I wouldn't have been very happy.Had I not seen him then.....Without your help, I could have never finished that task.I have a headache today. Otherwise I could take part in your football team.He telephoned to inform me of your birthday, or I would have known nothing about it.多亏了他打电话告诉我你生日的事，要不然我什么都不知道。as if / as though （好像）+从句这种用法要注意，主句是正常的陈述句，从句是虚拟语气。与将来相反 - Would / could / might +do例句：She can tell you the whole event with every details as if she had been there when it happened.当然，如果你说的是一种很可能发生的推测，也可以不用虚拟语气。It is (high / about) time (that）sb. did / sb. should + doIt is high time that we should work hard / that we worked hard for the test.与过去相反 - Had done（或者could have done）与将来相反 - Would / could / might +doI wish (that) I were able to help everyone of you to pass the IELTS.I would rather she had not told you what happened last summer.老师会告诉你 sb suggests that sb (should) do sth.advise, suggest, propose, order, demand, request, desire, insist在表示“坚持”、“命令”、“建议”、“要求”等后的宾语从句要用虚拟语气。这类动词有人归纳为“一个坚持（insist）、两个命令（order， command）、三个建议（advise， suggest， propose）、四个要求（demand， require， request， ask）”，这类虚拟语气由“should+动词原形”构成，其中的should在美国英语中通常可以省略。如： He insisted that I （should） go with them. 他坚持要我同他们一起去 He ordered that it （should） be sent back. 他命令把它送回去 The doctor advised [suggested] that he （should） not smoke. 医生建议他不要抽烟 He requires that I （should） appear. 他要求我出场还是那句话，如果大家不熟练的话，还是不要乱用。。。想尝试的童鞋，可以结合口语题卡或者作文题目多造几个句子练练
