You start referring to Facebook as “facey.”
“Voce esta no facey?“(“Are you on Facebook?”) might sound like a disarming question if you’re a recent arrival in Rio, but you’ll soon figure out that you’re being asked if you have a Facebook account. You’ll probably cringe the first few times you hear it, but you’ll soon catch yourself asking the same question.
Next steps: You start referring to shopping malls as “shoppings” and to Caipirinhas as “caipis.”