1、表示与现在事实相反的情况
从句:If+主语+动词一般过去时(Be动词用were)
主句:主语+ should/would/might/could+do:
eg:If I were you,I would take an umbrella.
如果我是你,我会带把伞。(事实:我不可能是你)
2、表示与过去事实相反的情况
从句:If+主语+had+done
主句:主语+should/would/might/could+have done
eg:If I had got there earlier,I should/would have met her.
如果我早到那儿,我就会见到她。(事实:去晚了)
3、表示与将来事实相反
从句:①if+主语+were to do
②if+主语+should+do
③if+主语+动词一般过去式(be动词用were)
主句:主语+should/would/might/could+do
eg:If she were to be here next Monday,I would tell her about the matter.
如果她下周一来这儿的话,我就会告诉她这件事的始末。(事实:来的可能性很小,不可能)
1.与现在事实相反的虚拟语气,if从句中的谓语用过去式(be用were),主句用would/could/mightshould+动词原形。
If I had enough money, I would buy myself a computer.
我如果有足够的钱,会为自己买一台电脑。
If I were you, I would forgive Mary.
如果我是你,我就会原谅玛丽。
2.与将来事实相反的虚拟语气,从句谓语过去式(be用were)/should+动词原形/were to+动词原形,主句谓语would/could/might/should do.
If I saw/should see/were to see him tomorrow, I would invite him home.
我如果明天见到他,会邀请他到家里来。
·If I were to do the job, I would do it in a different way.
要是我来做这项工作,我会用另一种方法。
3.与过去事实相反的虚拟语气,主句谓语should/would/could/might+have+过去分词,If 条件从句的谓语形式had+过去分词词。
If we had had enough rain last year,we could have gained a good harvest.
如果去年雨水充足的话,我们可能会有一个好收成。
If the weather had been nice yesterday,we would have gone for a picnic.如果昨天天气好的话,我们就去野餐了。
4. wish后的宾语从句用虚拟语气,从句的谓语形式虚拟情况
与现在事实相反用:过去式(be用were)
与过去事实相反had+过去分词
与将来事实相反would/ could/might+动词原形
I wish (that) I were a bird and could fly freely in the sky.
我希望我是一只鸟,可以在天空中自由地飞翔。