I really appreciate your invitation, but I must decline it.

非常感谢你们的邀请，但我不得不谢绝。

youdao

Sir, I am honoured by your proposal, but I regret that I must decline it.

先生，你的求婚使我感觉荣幸，可惜我除了谢绝别无他法。

youdao

I thank you for the invitation, but I must decline.

我很感谢你的邀请。可是，我必须拒绝。

youdao

I really appreciate your offer, but I must decline it.

我非常感想你们给的条件，可是我得拒绝。

youdao

I can't but decline his offer.

我不得不拒绝他的提议。

youdao

I can't but decline his offer.

我不得不拒绝他的提议。

youdao