Turn off the narrative, the inner monologue, the train of thought. You probably can't shut it down completely - that's okay, just let it go each time you notice it.
Meanwhile, the back of your mind is constantly generating chatter. Passively eavesdrop on that chatter. You won't be able to make much of it out, it's mumbling and disconnected scraps, like someone else's conversation across a cafe. That's okay. Just kind of tune in; if you get stuff, you get stuff.
Being still enough to listen relaxes your body, and the listening-state and the space you create for it soon fills up with dream-gibberish - and that segues smoothly into actually dreaming.
I mean, maybe not precisely as speech, but y'know, the undergrowth that your actual articulated thoughts stick out of.
You can't tell me that when you stop actively driving the process, it's a complete ghost town in there, because that's just too terrifying to contemplate.