Must , can/could, may/might 的用法

must

1.must 表示推测时， 只能用于肯定句。

must do 对一般时的肯定推测

must have done 对过去发生的事情作出的肯定判断

must be doing/do 对现在的动作进行肯定推测

他们买了一辆新车。 他们一定很有钱。

They have bought a new car. They must have a lot of money.

他现在一定在看小说。

He must be reading novels now.

路是湿的。昨天晚上一定下雨了。

The road is wet. It must have rained last night.