Best way to learn the local slang nobody teaches in class?

OP here — my best source has been just asking younger friends 'how would YOU actually say this?' after I say the textbook version. The gap between the two is exactly the slang I need, and they love teaching it.

Local social media, memes and comment sections are a goldmine — that's where the real, current, unfiltered language lives. Half of it makes no sense at first, and looking it up teaches you more than any class.

Local TV shows and comedy specifically — not the news, which is formal. Comedy is built on slang, timing and cultural in-jokes, so if you can follow a stand-up set, you've genuinely arrived.

I keep a running note on my phone of slang I overhear, then check it with a friend before using it — because some of it is rude or region-specific in ways a learner can't detect. Collect first, deploy carefully.

Be a little careful — slang is very tied to age, region and setting, and hearing it once doesn't mean it's safe everywhere. I dropped a casual phrase in a work meeting that landed very wrong. Test new slang in low-stakes company first.

A tandem partner is perfect for this. In exchange for helping with their English, mine explains not just the slang but WHEN and with WHOM it's okay — the context textbooks never give you.

Podcasts aimed at natives (not learners) were my unlock — casual hosts chatting is the register you actually need. Slow, painful, then suddenly you're laughing along at the jokes. That's the goal.

And don't force it — nothing sounds worse than a learner cramming in slang that doesn't fit them yet. Let it arrive naturally as you understand more; using it correctly is far better than using lots of it.