So what? … thì đã sao

Thì đã sao? means "So what?" It comes after a fact someone has raised, and it brushes that fact aside: it doesn't matter, or it changes nothing. Tôi về trễ một chút thì đã sao? So what if I'm home a bit late?

The pattern is the fact, then thì đã sao. The đã here doesn't point to the past; it sharpens the challenge, as if asking "what harm has that done?" Nào at the end makes it sharper still: thì đã sao nào?

As a reply on its own, Thì sao? or Thì đã sao? shrugs off what someone has just said. Rồi sao? is close, and can also simply mean "And then what?"

It's blunt. About yourself, or between friends, it sounds defiant but acceptable, and it can be encouraging: Thua một trận thì đã sao? So what if we lost one match? Said to someone older or more senior, it sounds rude, so keep it out of polite conversation. A gentler way to say "it doesn't matter" is Có sao đâu or Không sao.

You'll hear it in conversation and in film and TV dialogue, and you'll read it in headlines and opinion pieces that want a strong voice.