Is it possible to learn a language while sleeping

Hypothetically? No. Not learn, anyway. Your mind needs to be awake to organise the data.

You’ll probably absorb random information just as you’re waking up, when your mind’s at its most lucid and suggestible. But in this state it won’t be able to assimilate the info correctly. It will just make random connections and subconscious associations.

So not a method I’d use. If I did, I’d probably find myself in a restaurant in Rome asking for an enema.

Having said that, it you could use it to improve pronunciation skills.

you could use it to improve pronunciation skills.

I bet only marginally. Again any benefit would come from half-waking periods, not actual sleep, and I bet it would just help you get the rhythm and intonation patterns of the language, if that.

When I was at the RAAF language school in Australia, the teachers there specifically advised NOT to try this method as it impinges on proper sleep patterns.

So did it work, OP?

Probably sleeping.

I don't think it would help with learning. However, I always seem to understand Korean conversations better while I'm sleeping on the metro.