1) I am writing to convey my gratitude to you for...

我写信是为了表达对你的感激之情。

2) I would like to take the opportunity to express my appreciation for your timely help and assistance.

我想利用这个机会，因为你的及时帮助和协助表达我的感激之情。

3) Many thanks for all the things you have done in helping us to...

非常感谢你为帮助我们...所做的一切。

4) Words fail to convey my gratitude to you.

我对你的感激之情难以言表。

5) My true gratitude is beyond any words/description.

任何语言都不能表达我真挚的谢意。

6) On behalf of...I would like to extend my sincere gratitude to you for...

我仅代表...因为...表达我诚挚的谢意。

7) I really don’t know how to express my gratitude for your help.

我真的不知道如何表达你对我的帮助的感激之情。

8) With deepest gratitude, I write to you here a few lines.

我写这几行字是为了表达我诚挚的谢意。

9) What you did gave us a deep impression and we hope to express our thanks to you.

你所做的给我们留下了深刻的印象，我希望向你表达我们的感谢。

10) I am writing to express my thanks to you for.... If it had not been for your help, I would have +v-ed

我写信是因为你的帮助而感谢你。如果没有你的帮助，我就会...

11) Thanks to your generous/selfless/kind help, without which I wouldn’t have made such great progress.

感谢你慷慨/无私的帮助，没有你的帮助我就不会取得如此大的进步。

12) It was your generous help that enabled me to have a better understanding of...

是你慷慨的帮助让我对...有了更好的理解。

1) I must thank you again for your generous help.

我必须再次因为你的慷慨相助而感谢你。

2) From what you did I learn that helping others is a traditional virtue, so I’ll keep it up.

从你所做的事情中我学到帮助别人是一种美德，所以我也会将它传承下去。

3) Please accept my heartfelt appreciation again, I’m eagerly expecting our next meeting.

请再次接受我由衷的感谢，期待我们下次见面。

4) I am so proud of having such a generous friend as you, and I will always be there as long as you need.

很骄傲拥有你这样慷慨的朋友，只要你需要我也会一直在。

5) I wish there were a better word than “thanks” to express my appreciation for your generous help.

我希望能有比“谢谢”更好的词来表达我对你的感激之情。

6) It is your unreserved help that enables me to obtain this splendid opportunity of ...

是你毫无保留的帮助让我获得了这个极好的机会...