We need to write a thank-you letter.

我们需要写作一封感谢信。

He decided to send her a thank-you letter.

他决定送给她一封感谢信。

On Father's Day, I wrote a thank-you letter to my dad.

父亲节那天，我给爸爸写了一封感谢信。

And the formal thank-you letter after the interview?

那么，应聘者要不要在面试后发一封正式的感谢信呢？

An appreciation letter can be written simply and in the same vein as a thank you letter.

一个可写感谢信简单，同样作为感谢你的信。

I wrote a Thank You letter to Paulo Coelho , to share my appreciation and this little story.

我写了一谢谢你的信，以保罗科埃略，分享我的赞赏和这个小故事。

I have only been able to write one thank you letter because physically I couldn't reply to each person.

这是真的，我写下了‘谢谢你，我不会让你失望的’。

I have a thank you letter I need to write but there are two more people I need to send a letter to also and it would be efficient to send them at the same time.

我要给你写封感谢信，但是我还得给另外两个人写信，只需要写一封信，同时发给他们，这样更有效率，因为还没给他们写，所以也没给你写。

After the interview take notes about what you were asked and how you answered. Send a thank you letter or email which reinforces your interest in the job.

面试之后，记录下你被问到的问题和你所做的回答。发出感谢信，这样可以让对方知道你对这份工作真的很有意。

We thank you for you letter enclosing a cheque in part-payment of your account, but would pint our that the sum still outstanding is considerable.

感谢贵方来函附寄一张支票以部分付清帐款，但是我方要指出，未付的数目仍然相当庞大。