should do 和后退一个时态都是虚拟语气的使用形式吗？那么何时用should，何时后退时态？

Question

如题所述

Answer 1

有三个时态的虚拟语气，都有用到should
（if引导的）从句中的v. 主句中的v.
现在 did / were should / would / might / could + do
过去 had done / been should / would / might / could + have done / been
将来 were to / should + do should / would / might / could + do
给你造几个句子，看看能不能更清楚：
现在 If I were a train, I should travel to all the splendid scenes in this planet.
过去 If you had not been a queer, you should never have broken your mom's heart.
将来 If our team were to undermine the opponent's reputation for our own good, we should be sorry.本回答被提问者和网友采纳

Answer 2

should 动词原形 ② 谓语用动词过去式 ③were to do 主句谓语动词形式 A:时态是与虚拟语气关系密切的相关语法知识，唯有熟练掌握时态，才能掌握好虚拟