题目

请教有个句子 不理解
Airlines can make special offers that are sometimes cheaper than train tickets.
There are also shuttle and commuter flights between some major cities that are close to each other.'
请问这两个句子中that 是起什么作用?在我印象里that很少后面直接跟be的,for ex...that we talked..是定语从句吗?

提问时间：2021-03-31

答案

两个that 在句中都引导的是定语从句.分别回指前面的先行词offers 和cities,并且在定语从句中做主语.
that后面是否跟be动词或其它动词,完全取决于that在从句中做主语时所需要的动词.
如: He bought a book that / which is interesting to me. 他买了一本我感兴趣的书.
句中的that 和which 回指前面的先行词book, 同时在定语从句中做主语.因为后面是形容词interesting,当然就要用be 动词.
而第二个问题,我不知道你完整的句子是什么,只能自己猜测一下并举例:
This is the topic that we talked about.
that引导的确实是定语从句,但在从句中做的是宾语,即talk about的宾语.