"He is asking your wife."
Translation:Ptá se vaší ženy.
Ptát se is imperfective, while zeptat se is perfective. You can read a bit about the difference here (section 4, Aspect): https://en.wikipedia.org/wiki/Czech_conjugation#Aspect. The perfective cannot be used in this exercise, because it is clear from the English sentence the action is underway at the present time.