must not have

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/23 19:22:58
mustnothavemustnothavemustnothave没有mustnothavedone,表示对过去事情肯定的推测用musthavedone,否定的推测只能用can''t/couldn''th

must not have
must not have

must not have
没有must not have done,表示对过去事情肯定的推测用must have done,否定的推测只能用can't/couldn't have done.
在反意疑问句中要根据具体的时态来定,如果句中有具体的过去时间状语的话就用did/didn't we,反之没有具体的过去时间状语,强调对现在影响时,就用完成时.
例如:He must have attended the party last night,didn't he?
He knows everything about it,so he must have read the book,hasn't he?