couldn't have done和couldn't do的区别

couldn't have done和couldn't do的区别 should have done和shouldn't have done,couldn't have 求两组英语句型的解释could have done 和 couldn't have doneshould have done 和 shouldn't have done couldn't have done和mightn't have done有什么区别 should have done ,shouldn't have done.could have done,couldn't have done 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? they couldn't have done better是什么意思 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 have done 有 不可能的意思吗?问题二它和cant have done的区别 情态动词can't have done 和couldn't have done 有什么区别吗对过去发生的事情否定猜测用can't have done 或couldn't have done ,两者有区别吗?比如 He can’t have gone to Beijing for I saw him a minute ago. 能换成He couldn couldn't have done,不可能已经?请举例说明用法? 英语中何时使用wouldn,t have done shouldn,t have done couldn,t have done needn,t have donewouldn have done shouldn have done could have done needn have done 呢 Whitout you _____ us, we couldn't have done it.A.helped B.helping C.being helped D.having helped 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? 区别shouldn't have done 和 needn't have done i don't think he could have done better than that,()?A.do i B.don't i C.could he D.couldn't he 1 wish I __to repair the bike .I only made it worsea)did not try B)wouldn't try c) had not tried d) wouldn't have tried 2 she__it ,beacuse she was not on the spot thena)shouldn't have done b) wouldn't have done c)mustn't have done d)couldn't have don couldn't have done?couldn't have done究竟表示对过去的否定推测,还是表示本不能做到的事做到了?