他是一个对朋友非常忠实的人。

Tā shì yí gè duì péngyou fēicháng zhōngshí de rén.

He is someone who is very loyal to his friends.

这条狗对主人特别忠实，从不乱跑。

Zhè tiáo gǒu duì zhǔrén tèbié zhōngshí, cóng bù luàn pǎo.

This dog is especially loyal to its owner and never runs around.