關於關代的主格與受格

He is known as a man _____people around him judge a liar.
空格中填的關代為受格whom

但是
He has such a noble character and praised as a man ____no one would think will commit crimes.

這句的空格填的卻是主格who

請問該如何判斷何時選用主格、何時選用受格?
感謝ˇ
4 answers 4