As they are expected to be hungry after their long journey,

问题描述:

As they are expected to be hungry after their long journey,
我想知道这里的to be +形容词是什么用法,都在什么情况下这样用

to 不是和be 连在一起的,是一个固定搭配 expect to do sth,而在be 动词只是联系动词不可以单独做谓语,系表结构就是说在be 动词后加的是表语,能承当表语的也只有名词和形容词了