User blog comment:Datovidny/Trivia Quiz/@comment-3048006-20131208180154/@comment-5801603-20131209155254

Click on somebody's name, and three options should come up, Contributions, Talk Page and PRivate Message. Click Private Message.

On the other chat it's very similar, and I've used it before.

The problem is, if you're chat mod or admin, you might accidentally kick someone when PMing. The options are very close together and once I was attempting to PM someone and I accidentally kicked them. Especially as this is a kind of frantic pm contest, it's easy to misjudge. I wasn't even in a hurry and I still kicked someone. :/