"Are you reading a menu?"
Translation:Lees je een menu?
No, because Lees is a verb. The verb doesn't need another verb to be a question.
In dutch we generally use the present simple for the present simple AND the presenr continious. Dutch has a present continious but it is almost always exchangable with the present simple.
The verb is conjugated this way: ik lees je leest hij/ze/het leest
However, when the subject of a question is je/jij, the -t at the end of the verb is removed.
E.g. "je leest de krant" as a question is "lees je de krant?"
This happens with every verb, not just lezen.