From 23 skidoo to kickin’ it — and beyond!
You’ve asked for “a cool way to ask if someone is [being] cool [right now]”, something with the same feel to it as seen in the Brazilian Portuguese slang expression suave na nave. Although translated literally that short snippet might run along the lines of “chillin’ in the (space-)ship”, I wouldn’t try to find a literal translation for those words, because those never work for slang.
Slang is always in a state of flux; who still remembers twenty-three skidoo and can identify when that expression was in vogue? Slang has a short shelf life to begin with, and it just isn’t all that portable.
For one thing, one generation’s cool kids become the next generation’s uncool old farts, and the generation following that one has forgotten the first one completely:
But for another thing, even contemporaneous slang isn’t portable from one place to another, or one age group to another, or one ethnic group to another. English has upwards of 400 million native speakers today, and several times that many second-language speakers. The slang of young teenagers will different from that of thirty-somethings, as will city slang differ from country slang.
All those things aside, the best thing that my laborious field research :) sampling the youth in my neighborhood could come up with would be something like kickin’ it or just plain chillin’, both of which work as both answers as well as questions if you start them off with a You... placed in front.
- “’S up?”
“Just kickin’ it.”
- “You kickin’ it?”
Now, those phrases I dug up from the local rakes may well be over the hill already. For the guaranteed newest in contemporary slang, listen to the language of teenaged girls, as research has shown that they are often the source of this sort of language change.
See ya later, alligator!
I should also point out that suave na nave is also a slang expression with internal rhyme, something which often elicits a response that rhymes as well. If you’re Brazilian, think of sayings like de boa na lagoa or de leve na neve. What those two phrases mean literally or figuratively doesn’t matter for our purposes here; the point is that they rhyme, and little rhymes like this can be very “catchy” — often repeated and quick to spread.
One older, English-language example of a rhyming expression and paired rhyming response (which means nothing like you asked for, mind you) is:
- “See ya later alligator!”
“In a while crocodile!”
You don’t hear that one very much anymore, but you used to. There are thousands of slang expressions in English, and probably from every era, too. To use these naturally, you’ll need to pick them up live from your social set.