I've got a trombone beginner that still can't tongue (he started remote). Makes a good tone, but the sound is a little small.

I've tried every trick I know w/little success. He can get it once or twice, but can't replicate or retain it. He's smart and trying hard, but to no avail.

He speaks multiple languages and I don't think that English is his first language. Don't think that is the problem-just background info.

Articulation is hardly ever a problem for my students, so I'm in need of new ideas.

What's your go to trick for kids that struggle w/ articulation?