一、虚拟语气有哪些用法
1.虚拟条件句的三种基本类型：与现在事实相反、与过去事实相反、与将来事实相反。
2.与现在事实相反，条件从句的谓语用过去式，主句谓语用should（would,could,might）+动词原形。
3.与过去事实相反，条件从句的谓语用过去完成时（had+过去分词），主句谓语用should（would,could,might）+have+过去分词。
4.与将来事实相反，条件从句的谓语用过去式（be通常用were），主句谓语用should（would,could,might）+动词原形。
二、虚拟语气语法知识
英语中的各种语气：
1，陈述语气：I like apples 我喜欢苹果。（肯定）
I don&39;t like apples我不喜欢苹果（否定）
2，疑问语气：What&39;s your name？你叫什么名字？
Do you like apples?你喜欢苹果？
3，祈使语气：Open the door 打开门
3，虚拟语气：If I were you, I would forgive her如果我是你，我将会原谅她。
虚拟语气结构讲解：
1，与现在的事实相反：从句用过去式，主句用would/could/might/should/+动词原形
例如；If I had time ，the classroom would be so clean 如果我有时间，教室将会更加干净。
2，与过去的事实相反：主句用would/could/should/might/+have+ done , 从句中过去完成时
例如；If I had finished my homework ，I would have passed that test
如果当时我完成了我的做，我就能够通过我的考试了。
3，与将来的事实相反：主句用：should/could/would/might/+动词原形，从句用should do （可能性最大），过去式（可能性一般）were to do （可能性最小）
If it should snow tomorrow，I would make a snowman 如果明天下雪，明天我将对一个雪人
If it snowed tomorrow，I would make a snowman 如果明天下雪，明天我将堆一个雪人
If it were to snow tomorrow ，I would make a snowman 如果明天下雪，我将对一个雪人
虚拟语气的倒装形式
If I had worked hard ，I would have finished it 如果当时我努力工作，我就已经完成它了。
=Had I worked hard ，I would have finished it
If it should snow tomorrow ，I would make a snowman 如果明天下月，我将会对雪人
Should it snow tomorrow ，I would make a snowman
If it were to snow tomorrow ，I would make a snowman
=Were it to snow tomorrow ，I would make a snowman
