sit in

sit in  {v.}
1. Быть членом чего-л., принимать участие.
We're having a conference and we'd like you to sit in.
also sit in on: To be a member of; participate in.
We want you to sit in on the meeting.
2. Посещать, но не принимать участие. Часто исп. с "on".
Our teacher was invited to sit in on the conference.
Категории: (исп.) {v.}