用作宾语的从句叫做宾语从句，一个及物动词后面加的从句一般就是宾语从句，介词后面跟的从句也是宾语从句，宾语从句常见的结构就是：动宾和介宾两种形式。
宾语从句1.引导宾语从句的关联词有从属连词、疑问代词、疑问副词、缩合连接代词、缩合连接副词等。如：
He told us he felt ill. 他对我们说他感到不舒服。(关联词是从属连词 that)
I know he has returned. 我知道他已经回来了。(在非正式文体中关联词that被省去)
That he ever said such a thing I simply don’t believe. 我简直不相信他曾说过这样的话。(that从句位于句首时，that不可省去)
2.宾语从句亦可用作介词的宾语，如：
He was deeply displeased by what had occurred that day. 他对那天发生的事感到很不快。(what引导的从句是介词by的宾语)
I walked over to where she sat. 我走向她坐的地方。(where引导的从句是介词to的宾语)
I am curious as to what he will say. 我很想知道他要说什么。(what引导的从句是复合介词as to的宾语)
