could't与couldn't的区别?这两个词都存在吗?表达的是一样的意思吗?

couldn't与can't的区别! can't与couldn't的区别 couldn't have done与couldn't区别以及当could have done表示对过去的猜测时,could have done与could有什么区别? could和 must和 couldn't 的区别和用法? could't与couldn't的区别?这两个词都存在吗?表达的是一样的意思吗? could和couldn't的不同 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 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? couldn't don't have to needn't的区别 can’t have been与couldn’t have been的区别? why not,why didn't,why couldn't的区别 couldn't和shouldn't的区别,急要 can't与couldn't区别,做题初三总是好两个一起来,怎么区分,特别用could I提问时分不清, But I could ,couldn't?翻译 can't和couldn't区别? can,t与don,t区别,didn,t与could,t区别