中间部分：

Give advice:

In my humble opinion, you would be wise to take the following action:

在下认为，如果你能采取以下措施，将是一种明智的选择。

I hope you will not find it too forward for me to suggest that you...

请原谅我的直接，不过，希望你能___________。

In my experience, it seems that _______ would make sense in your situation.

从我的经验来看，针对你的情况，似乎________会有帮助。

At the risk of overstepping my boundaries, allow me to suggest that you____。

请原谅我的冒昧，不过我建议你_____________。

Gratitude

I truly appreciate your kindness.

我很欣赏你的仁慈。

I am grateful to you for...

非常感谢你_________________-。

I appreciate it more than I can say.

我对你表示万分感谢。

I can never thank you enough.

万分感谢。

I wish there were a better word than " thanks " to express my appreciation for your generous help.

其实，对你的帮助岂能用"谢谢"儿子可以表达的。

It was kind and generous of you to do this for me, and I appreciate it more than I can say.

你对我如此慷慨，真是对您感激不尽。

Many thanks for your kindness and hospitality.

非常感谢你的仁慈和好客。

Now we have arrived back home safe and sound.

现在我已经安全到家。

Thank you from the bottom of my heart for...

我打从心底谢谢你（真诚地感谢你）。

Thank you again for your kindness.

谢谢你的好意。

Apology

Please accept my sincerest and deepest apology.

请接受我最诚挚、最深刻的道歉。

I apologize most sincerely for...

我诚挚地对___________向你道歉。

I am truly sorry to have done...

我对________向你表示道歉。

Please forgive me...

请原谅我曾__________。

I owe you an apology...

我为______向你道歉。

I regret to inform you that I am unable to do..

很遗憾地告诉你，我没法___________。

I am so sorry to have put you through so much trouble...

很抱歉给你带来这么多麻烦，__________。