If she could sew,she would have made a shirt.

If she could sew,she would have made a shirt。这个句子存在的问题是If虚拟语气中主从句搭配混乱,主句表示同过去事实相反时,从句则和现在事实相反。答案貌似为：If she could sew ,she would made a shirt。与现在事实相反的假设。她现在要是会缝纫的话,她就能做一件衬衣了。不过我认为原句也是对的 可翻译为 她要是会缝纫的话,她早就做成一件衬衣了。如果非按规则写成If she had sewn,she would have made a shirt。则无法表达出她一贯的能力,与原句意思不一样。所以虚拟条件句中的could do表达的是 与一贯能力相反 主句可以用过去将来时或过去将来完成时。