sie wissen nicht, was

you don't know what

→ sie
phrase Uncommon #22,252
you don't know what “Sie” can mean formal “you” or “they,” depending on context.
GE: Sie wissen nicht, was ich meine.
EN: You don't know what I mean.

Vater, vergib ihnen; denn sie wissen nicht, was sie tun.

Father, forgive them, for they know not what they do.

Sie wissen nicht, was er mir bedeutet!

You don't know what he means to me!

— Zwei glorreiche Halunken (1966)

Sie wissen nicht, was sie sagen.

They don't know what they're saying.

— Dune: Part Two (2024)

Sie wissen nicht, was das ist?

You don't know what that is?

— Die Legende vom Ozeanpianisten (1998)

Sie wissen nicht, was ich weiß.

You don't know what I know.

— Eine Frage der Ehre (1992)

Sie wissen nicht, was er mir angetan hat.

You don't know what he did to me.

Sie wissen nicht, was schiefgelaufen ist.

They don't know what went wrong.

Vergib ihnen, denn sie wissen nicht, was sie tun.

Forgive them, for they know not what they do.

Sie wissen nicht, was Sie gerade getan haben.

They don't know what they've just done.

— Edge of Tomorrow (2014)

Sie wissen nicht, was es mir bedeutet, dass Sie meine Nachbarin sind.

You don't know what it means to me that you are my neighbor.

— Picknick (1955)

Sie wissen nicht, was sie tun.

They don't know what they're doing.

— Solaris (1972)

Sie wissen nicht, was diese Kraft bewirken kann.

They don't know what this power can do.

— Atlantis - Das Geheimnis der verlorenen Stadt (2001)

Sie wissen nicht, was ihnen geschieht.

They don't know what's happening to them.

— Malcolm X (1992)