"The boy looks there, but does not go there."

Translation: Odanéz a fiú, de nem megy oda.

[AnCatDubh]

Why not ‘odamegy’?

[RyagonIV]

You're negating the action - he does not go there. He doesn't move at all. So nem needs to be in front of the verb stem, displacing the suffix.

[GregWood15]

But aren't we contrasting "odanéz" with "odamegy"?

[BigWayne19]

------ and the "nem " kicks "oda " behind the verb . . .

Big 18 feb 21

[bnyugat]

when do we use 'de' for but versus 'hanem'?

[mizinamo]

hanem is for "not A, but (instead) B" contexts - here, the first part is not a negative that you are mentioning only to discard it and mention the real thing. He does, after all, look there, and the going there is not an "instead" action. So hanem would not be appropriate here.