was du da machst

what you're doing there

→ was
phrase Rare #31,213
what you're doing there Used in an embedded question or as a descriptive clause. “Da” can refer to a place or situation and often adds emphasis, as in “what you're doing there.”
GE: Ich verstehe nicht, was du da machst.
EN: I don't understand what you're doing there.

Erklär mir, was du da machst.

Explain to me what you're doing there.

Weißt du, was du da machst?

Do you know what you're doing?

— Die amerikanische Nacht (1973)

Das ist gefährlich, was du da machst.

What you're doing there is dangerous.

— Die Frau im Nebel (2022)

Was du da machst!

What you're doing!

— Hass (1995)

Es ist mir zu gruselig, was du da machst.

What you're doing there is too creepy for me.

— Good Bye, Lenin! (2003)

Weißt du überhaupt, was du da machst?

Do you even know what you're doing?

— Die Ironie des Schicksals, oder Genieße Dein Bad! (1976)

Du wirst ihm erklären müssen, was du da machst, Beto.

You'll have to explain to him what you're doing, Beto.

— Elite Squad: Im Sumpf der Korruption (2010)