He finds watching movies frustrating because the speak too quickly,

题目

He finds watching movies frustrating because the speak too quickly,
如果在finds和watching之间加个that可以吗?为什么要用watching啊后面有谓语动词吗?不应该是is frustrating么

答案

可以说 he finds that watching movies is frustrating. 如果是这样的话,watching movies 是从句中的主语,就要搭配动词is.
但是还可以说find sth + 形容词,比如find it interesting.