C1
S + can't have + V3 · S + mustn't + V0
can't have V3 与 mustn't have 的区别
讲解
这两个说法听起来很接近，但作用不同。can't have V3 是推断：我确信这件事没有发生。mustn't V0 是禁止：你不许做。对过去的否定推测总是用 can't have 或 couldn't have，不用 mustn't have。 常见错误：推测时不能用 mustn't have：He mustn't have finished ✗, He can't have finished ✓。
例句
He can't have finished already.
他不可能已经做完了。
You mustn't touch the wiring.
你不许碰电线。
She couldn't have known about the change.
她不可能知道那个变动。
Guests mustn't smoke in the corridor.
客人不得在走廊里吸烟。
练习
通过选择题测试你的掌握程度
高效学习“S + can't have + V3 · S + mustn't + V0”
语法点“S + can't have + V3 · S + mustn't + V0”（can't have V3 与 mustn't have 的区别）是 CEFR 5 级别的重要结构之一。要熟练运用这个结构，你需要弄清楚它的使用语境，并经常练习。
学习小贴士：把例句大声朗读多遍，培养自然的语感反应。然后试着结合自己的生活情境造句。用发音按钮听标准发音并跟着练习。
你也可以查看完整课程“”，更深入地了解相关的语法和词汇。