诚心诚意的英文：
(saying) eager and sincere

参考例句：

"Nor did she put the question altogether idly, but, for the moment, with a portion of genuine earnestness;"
她提出这样一个问题绝不是漫不经心的,就当时而论,她确实带着几分诚心诚意

Iago, as if in earnest care for Othello’s peace of mind, besought him to beware of jealousy.
伊阿古做出假装诚心诚意地关心奥瑟罗精神上的安宁，劝他当心不要吃醋。

Most earnestly did she labour to prove the probability of error, and seek to clear one, without involving the other
她诚心诚意地想说明这件事可能与事实有出入，竭力想洗清这一个的冤屈，又不愿叫另一个受委屈。

saying是什么意思：
n. 话；谚语；言论
v. say的ing形式

To say this is worthwhile.||It is worthwhile to say this.
这话值得说。

He popped in to say hello.
他匆匆进来说声你好。

As they say, honesty is the best policy.
常言道，诚实是最佳策略。

eager是什么意思：
adj. 热切的；热心的；渴望的，急切的

She is eager for success.
她渴望成功。

They are eager to have a glance at the bride and bridegroom.
他们都急切地想看一看新郎和新娘。

The man is an eager beaver.
那人工作很卖力。

sincere是什么意思：
adj. 真诚的，衷心的；诚恳的；诚实的，忠实的；正直的

She‘s a sincere friend.
她是位忠实的朋友。

His sincereness moved me.
他的真诚打动了我。

Misfortune tests the sincerity of friends
患难见真情.