Could you please check in advance with all the people who have been invited to see who's going to attend? We also need to know who the facilitator will be.
ーCould you please check in advance with all the people who have been invited to see who's going to attend? We also need to know who the facilitator will be.
「招待した全員のうち誰が出席するか事前に確認してもらえますか？あと司会進行役の確認も必要です」
to check in advance で「事前に確認する」
people who have been invited で「招待された人々」
to attend で「出席する」
facilitator で「進行役」
ご参考まで！
カナダ 
