UC知道高中英语高手：关于must
来源：百度知道 编辑：UC知道 时间：2024/06/07 03:53:32
must用来表推测，我做了一趟整理，其中不少是借鉴了百度知道里的，可是出现了一个疑问，请大家指教。
must表推测时：
1. 对现在事实的推测，反义部分与must后的动词呼应。例：
You must be joking, aren’t you?
2. 对过去事实的推测：表动作时，用did；表状态时，用was。例：
Mr Green must have been punished for his being rude at the meeing, didn’t he?
She must have been a policewoman, wasn’t she?
3. 对已发生的过去的情况的推测，若陈述句谓语部分有must have done, 且有表示过去的时间状语，问句部分用didn’t；若无表示过去的状况，则用hasn’t或haven’t。
They must have gone there last night, didn’t they?
They must have arrived by now, haven’t they?
They must have been to the Great Wall, haven’t they?
疑点：例句中的She must have been a policewoman, wasn’t she?和They must have been to the Great Wall, haven’t they?
2. 对过去事实的推测：表动作时，用did；表状态时，用was。
所以She must have been a policewoman, wasn’t she?应该不是错句子把
must表推测时：
1. 对现在事实的推测，反义部分与must后的动词呼应。例：
You must be joking, aren’t you?
2. 对过去事实的推测：表动作时，用did；表状态时，用was。例：
Mr Green must have been punished for his being rude at the meeing, didn’t he?
She must have been a policewoman, wasn’t she?
3. 对已发生的过去的情况的推测，若陈述句谓语部分有must have done, 且有表示过去的时间状语，问句部分用didn’t；若无表示过去的状况，则用hasn’t或haven’t。
They must have gone there last night, didn’t they?
They must have arrived by now, haven’t they?
They must have been to the Great Wall, haven’t they?
疑点：例句中的She must have been a policewoman, wasn’t she?和They must have been to the Great Wall, haven’t they?
2. 对过去事实的推测：表动作时，用did；表状态时，用was。
所以She must have been a policewoman, wasn’t she?应该不是错句子把
must + 完成式。表示对过去的猜测，这条是原则
但是反义部分的时态是根据具体情况来断定的
She must have been a policewoman，是表示对过去的猜测
那反义部分就用wasn’t she
They must have been to the Great Wall
这里的have been to ，是词组，去过某地，是完成的，
所以他不是must + 完成式的形式，不表示过去，表完成
所以用haven’t
She must have been a policewoman, wasn’t she?
人死了呗，不然不能用这个的。要么这是哪个场景里的，之前的对白里有铺垫，所以就用了这个所谓的错句子
They must have been to the Great Wall, haven’t they?
没有时间状语修饰的话就用haven't ,假如有什么yesterday last year 等表示过去发生过 了的用 weren't