我最近都在忙于完成这项任务，所以很抱歉不能参加你的聚会。

I have been occupied in finishing this task recently, so sorry I can't go to your party.

youdao

我从上周开始就感觉不适，所以很抱歉我不能参加你的聚会。

I've been feeling ill since last week, so I am sorry that I can't go to your party.

youdao

这里是商务中心,下午我给您打过电话,由于您不在房内所以我无法急时联系到您真是非常抱歉.

This is business center .I called you in the afternoom .but you didn't stay in .so i am very sorry not to contact you in time.

youdao

So I'm sorry to have sort of the long gloom and doom, but it seems that it's only fair to let you know what you're getting into.

所以我抱歉说了这么的冗长的规矩，但是这合理让知道你们将要面对什么。

耶鲁公开课 - 死亡课程节选

I simply don't know because my history isn't very good. So, sorry.

我不知道，是因为我的历史学得不好。所以，很抱歉。

英国电影的魅力 - SpeakingMax英语口语达人