couldn't与can't的区别!

couldn't与can't的区别! can't与couldn't的区别 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? can’t have been与couldn’t have been的区别? can't和couldn't区别? didn't 和couldn't的区别, 请问英语中couldn't wouldn't needn't mustn't的区别与用法? couldn't have done和couldn't do的区别 can't too与couldn't too的区别Paul is kind,hardworking and intelligent,in a word,I can't think too highly of him.(怎么夸都不为过).能否用couldn't? can’t / couldn’t have couldn't have finished和 can't have finished 的区别 I can`t stand this class any more.与I couldn`t agree more!这两个 句型的区别,难道只有语义的区别吗? couldn't don't have to needn't的区别 may not/can't/couldn't/needn't/mustn't举例区别意思和用法 can't与cannot的区别是什么? why not,why didn't,why couldn't的区别 couldn't和shouldn't的区别,急要 can`t与mustn`t意义和用法的区别