sincerer

adj.真诚的；诚挚的

How can I persuade you that I am sincere? 怎样才能使你相信我是真心实意的呢?

I will oblige any sincere request. 我会答应任何诚意的请求。

I think he is sincere and quite without affectation. 我认为他为人诚挚，毫不做作。

Sincere congratulations on your son wedding please convey our best wish. 令郎喜结良缘谨此致以诚挚的祝贺并请转达最美好的祝愿。

Please accept my sincere thanks and best wishes. 请接受我诚挚的感谢和最美好的祝愿。