to participate (in sth)

I didn't take part in the conversation.

Participate!

I am not concerned with this affair.

I have to get up two hours earlier just to spend the whole day in the office for a 30-to-45-minute meeting I could have had by webcam.

The most important thing in the Olympic Games is not to win but to take part, just as the most important thing in life is not the triumph but the struggle. The essential thing is not to have conquered but to have fought well.