定义 / 说明
我们用 must、might、can't 等情态动词对当前情况做逻辑推断。这里它们不表示规则或许可，而是表示基于证据后的把握程度：must 是强肯定推断，might 是可能，can't 是强否定推断。该语法常用于“看不到全部事实，但可据线索推断”的场景。意义来自逻辑推理，不是直接目击的确定事实。
关键规则
- must + base verb：强肯定推断：She must be at work.
- might/may/could + base verb：可能性解释：He might be busy.
- can't + base verb：强否定推断：That can't be true.
- 此用法通常针对现在或一般当前状态。
- 不要与“许可”意义混淆：You may leave now 是另一种用法。
例句
- She must be at work. Her car is outside. - 她肯定在上班，她的车在外面。
- He can't be serious. - 他不可能是认真的。
- They might know the answer. - 他们可能知道答案。
- This could be the right address. - 这可能是正确地址。
- You must feel tired after that trip. - 你那趟旅行后肯定很累。
常见错误
- ❌ She must to be at work. -> ✅ She must be at work.
- ❌ He can't is serious. -> ✅ He can't be serious.
- ❌ They maybe know the answer. -> ✅ They might know the answer.