充滿自信的是confidential，.那么令人自信的怎么說？

應該是confident吧
make sb confident

confident 有信心的（不一定是自己）
self-confident 有自信的
confidential 機密的
convincing 令人信服的
sth. makes sb. confident in himself/herself
sth. makes sb. self-confident
（某事/物）讓人自信

令人自信恐怕無法用一個詞來表達。

confidential機密的；秘密的；極信任的

confident a. 自信的，有信心的，有把握的
常用句型有：be confident of sth./that。
例如：He is confident of victory./He is confident that he will succeed.(他對勝利充滿信心。)

令人自信：make sb feel confident about oneself
例如：She told me all these things to make me feel confident about myself.