名词性从句缺成分时多用what
不缺成分时用that
比如:I know that you are clever.宾语从句you are clever.是一个完整的句子,所以引导词就用that
I don't know where you live.从句里单独用you live是不完整的,缺地点状语,所以就要用连接副词where了
当然只是举了宾语从句的例子,主语从句,表语从句,同位语从句都属于名词性从句,情况类同.
名词性从句缺成分时多用what
不缺成分时用that
比如:I know that you are clever.宾语从句you are clever.是一个完整的句子,所以引导词就用that
I don't know where you live.从句里单独用you live是不完整的,缺地点状语,所以就要用连接副词where了
当然只是举了宾语从句的例子,主语从句,表语从句,同位语从句都属于名词性从句,情况类同.