"I can teach you everything."
Translation:Jeg kan lære dig alt.
Nogen lærer nogen noget = Someone teaches someone something/Jeg lærer jer dansk = I'm teaching you (all) Danish
Nogen lærer noget = Someone learns something/Jeg er ved at lære dansk = I'm learning Danish
In Danish, the word for "teach" and "learn" can both be "lære", it's just a matter of whether there is a second person involved or not (although it's not always the case, but just a general rule)
According to Den Danske Ordbog