If I were you, I should refuse his invitation.

如果我是你的话，我会拒绝他的邀请。

I never expected that he should refuse our invitation.

我决没料到他竟拒绝接受我们的邀请。

It would be most ungracious and impolite to refuse a simple invitation to supper with him.

连与他共进晚餐这样的简单邀请都拒绝会显得非常失礼，没有教养。

It would be rude of us to refuse their invitation.

我们拒绝他们的邀请会显得无礼。

Refuse I received his invitation yesterday but I did not accept it.

昨天我受到了他的邀请，但是没有接受。