can't和couldn't区别?

can't和couldn't区别? couldn't与can't的区别! can't与couldn't的区别 may not/can't/couldn't/needn't/mustn't举例区别意思和用法 didn't 和couldn't的区别, couldn't have done和couldn't do的区别 couldn't have finished和 can't have finished 的区别 couldn't do that和can't do that有什么区别 can’t / couldn’t have 表示否定推测只能用can't 和 couldn't 表示否定推测只能用can't 和 couldn't We couldn't watch until our homework was finished.为什么用couldn't 换成cann't 行不行 could 和 can 有什么区别? I couldn’t have hoped for a better outcome什么意思,另外can't have done和couldn't have done什么区别 couldn't和shouldn't的区别,急要 can have done和could have done有无区别?can't have done和couldn't have done有无区别?如果有,区别是什么? couldn t和 As she was very weak,she couldn't move这里的couldn't与can‘t区别,couldn't表示过去时? I couldn't bear it 和I couldn't bear this的区别