请问if里的那个条件句和虚拟语气是什么啊

你好，
随着说话人意图的不同，动词需要用不同的语气。英语中的语气分为陈述语气、祈使语气和虚拟语气三类。
英语中的虚拟语气可分为对现在、过去和将来的虚拟以及表达祝愿、坚决、决定、要求、命令等主观愿望的虚拟。
1. 表示假设的虚拟语气：主要用于对现在、过去和将来事实相反的假定。
A 与现在事实相反的虚拟语气
虚拟主句中用should/would/could/might+动词原形，条件从句中谓语动词用过去式。
1) If everyone knew first aid, many lives would be saved. 如果每个人都懂得急救知识，许多生命就会得以挽救。
2) If I were 20 years younger, I would start all over again. 如果再年轻20岁，我会从头再来。
B 与将来事实相反的虚拟语气
虚拟主语的谓语动词用should/would/could/might+动词原形，条件从句的谓语动词又三种形式，即should do, were to do和动词的过去式。
1) If it rained tomorrow, our plan would be put off.如果明天下雨，我们的计划救得推迟。
2) If the sun were to rise in the west, I would not change my mind. 即使太阳从西边出来，我也不会改变主意。
C 与过去事实相反的虚拟语气
虚拟主句用should/would/could/might+have+过去分词，条件从句中的谓语动词用过去完成式。
If you had worked hard, you would have easily passed the final test. 如果当时你努力的话，你就会轻松通过期末考试。
D 省略if 形式的虚拟语气
if虚拟条件句中有should, had 或were时，if可省略，从句中主谓要倒装。
Had I worked hard, I would have surely succeeded