Sometimes one can judge a man by the way people look, dress, and even act, both of which reveals their attitudes towards life and what they most interested in.
people 改成单数跟前面的a man对应。 both是两个，多个用among。 among which 强调其中某一种， reveal 还是要用单数形式 reveals。 最后词组be interested in。若是我会这么写： Sometimes one can judge a man by the way he looks, dresses, and even behaves, among which reveals his attitude towards life and what he is most interested in.
句中的man可以用he来指代，而且both指的是“两者都”动词应该是原形， 后面的what应该是宾语从句 建议改为Sometimes one can judge a man by the way he looks and dresses, both of which reveal hisattitude towards life and what
