很遗憾我不能参加你的婚礼。

Hěn yíhàn wǒ bùnéng cānjiā nǐde hūnlǐ.

I’m sorry I can’t attend your wedding.

这次比赛我感到很遗憾。

zhè cì bǐsài wǒ gǎndào hěn yíhàn.

I feel very sorry about this competition.

遗憾的是他没能参加。

yíhàn de shì tā méi néng cānjiā.

Unfortunately, he couldn't participate.