what you must do
Ich versuche herauszufinden, was du tun mußt.
I'm trying to figure out what you have to do.
Ich habe dir gesagt, was du tun mußt.
I told you what you have to do.
Ich versuche, in Erfahrung zu bringen, was du tun mußt.
I'm trying to find out what you have to do.
Ich muß dir wohl nicht sagen, was du tun mußt.
I probably don't need to tell you what you have to do.
Das ist vorerst alles, was du tun mußt.
That's all you need to do for now.