至于他是否会来参加，我不清楚。

Zhìyú tā shìfǒu huì lái cānjiā, wǒ bù qīngchǔ.

As for whether he will come, I'm not sure.

至于这件事，我们需要更多的信息。

Zhìyú zhè jiàn shì, wǒmen xūyào gèng duō de xìnxī.

As for this matter, we need more information.

至于他的意见，我并不太关心。

Zhìyú tā de yìjiàn, wǒ bìng bù tài guānxīn.

As for his opinion, I don't really care.