The truly free man is he who knows how to decline a dinner invitation without giving any excuse.

不用什么借口便知道如何谢绝人家邀请吃饭的人，才是一个真正独来独往的人。

youdao

I sincerely regret that owing to a prior engagement I am obliged to decline your kind invitation to dinner next Saturday.

由于有约在先，我不能接受下星期六与您共进晚餐的邀请，对此深表遗憾。

youdao

I sincerely regret that owing to a prior engagement I am obliged to decline your kind invitation to dinner next Saturday.

由于有约在先，我不能接受下星期六与您共进晚餐的邀请，对此深表遗憾。

youdao