Babs clicks her tongue (we're told it's the "q" in the Xhosa (I think that's what our friend speaks, correct me if I'm wrong) language). She squishes up her face and clicks her tongue at us, and we click back as a game. Kiddo, always wanting to be a part of things, figured out that she couldn't click her tongue, and sadly reported so, telling us it was what babies did.
But a few days later, she came close, so I carefully instructed her how to push up with her tongue on the roof of her mouth, then pull away fast. And soon she clicked! She was so excited to be able to join this little family game. And I was so proud of her for trying, then succeeding.