can have ddone 与could have done 的区别在于?

can have ddone 与could have done 的区别在于? i cant have you( )like this.A do B to do Cdoing Ddone 请问选什么为什么 情态动词的过去式主要是关于COULD的You______ him at the party last night.(CAN'T SEE不能表示过去么?)能不能用COULD'NT SEE作为CAN表猜测时候的过去式 就不一定要用CAN'T HAVE SEEN了情态动词没有过去式么?COUL 英语翻译Young people can have problems with their minds.Some students b3ecome worried because they have to study veryhard.Others have trouble gitting on well with people like their parents and classmates.Liu Wei,a Junior 2 student from Hefei,coul can not but与 have to 区别 英语翻译you don`t care for me,you don`t carry where i have been,i`ve done all i could,so that i could be with you.anyway you want,i do everything you need,maybe now you can see,that our love was went to be.but i was so wrong,always thought i coul 英语翻译I am a 1985 born male from London and would like to learn written Chinese.I can already read about 500 characters but I have difficulty writingbecause I don't remember their structure.I could help you with English in return.But first,coul can’t have been与couldn’t have been的区别? Can I have some Can Ll have a Can I have you can have been can’t +have done can I have some can you have wing? You can have Can i have a do nothing but do 与have no choice but to do 与can't but do