insincere

1. ADJ If you say that someone is insincere, you are being critical of them because they say things they do not really mean, usually pleasant, admiring, or encouraging things. 不誠懇的; 虛偽的[表不滿]

Some people are so terribly insincere you can never tell if they are telling the truth. 有些人虛偽得可怕，你絕對無法搞清楚他們是否在講真話。