Question

If she could sew, _____. A. she make a dress B. she would have made a shirt C. she wil make a dres

If she could sew, _____.
A. she make a dress B. she would have made a shirt C. she wil make a dress
if could 模式和if had done模式一样吗？ 不是有if did/ were ,would do模式吗，如果有she would make a dress 可以吗

Answer 1

第一个问题，两个是一样的，都是虚拟语气。表示假设。 不可以用would make a dress,因为if用的是chould，发生在过去，那么只能是过去的过去，表示完成，选择B。翻译过来是“如果她会缝纫的话，她早就给自己做一件裙子了”

追问

我看过一个answer说可以诶。。。。对现在的假设用if did/ were ,would do模式，，所以可以，，你说呢

追答

分情况，比如，If i were you, I would go to the cinema.(这是基于现在对将来的假设)。
If i were you, I would have been to the cinema.(这是基于过去的假设)。
对比这两个例句，你能理解了嘛，同学？

追问

就是说If she could sew ，she would make a dress,在意思上不成立吗

追答

你这样在意思上成立，语法上也没问题。但一般的假设都是对过去应该发生而没有发生的假设，所以B选项更合乎情理。表示如果她会缝纫，她早就已经给自己做了件衬衣了（实际上在过去没发生）。

Answer 2

这是个不对等的虚拟语气，if从句中是对一般情况的假设（现在变成过去），主句对过去的虚拟（就已经做了一件衬衣了。）

would have done 意思是"本来是或本来会..."

追问

我看过一个answer说可以诶。。。。对现在的假设用if did/ were ,would do模式，，所以可以，，你说呢

追答

从句中不能用would do，因为正常的条件从句中不能用will。本句的关键是，衬衫还没做，因为她不会缝纫。反过来讲，如果她会缝纫，她就做了一件衬衫了。这里做衬衫是说的过去的情况。

Answer 3

B. she would have made a shirt. 虚拟语气必须: would / should / might / could have +动词过去分词

追问

if could 模式和if had done模式一样吗？ 不是有if did/ were ,would do模式吗，如果有she would make a dress 可以吗

Answer 4

可以理解是错综时间条件句，马上就豁然开朗了。