"Where do you want to work?"
Translation:¿Dónde quieres trabajar?
The way I understand it is to pay attention to a verb that is in the 'to do' form... i.e. once there's a "to" before the verb it reads as the standard form of that verb '-ar'.. in this case: trabaj-ar.
This may be helpful in a rare case when there's just the one verb in a statement, e.g, this natural conversation: X: Where are you going? Y: To the farm. X: "to work?"
Someone correct me if I'm wrong.
"A dónde" means "To where", like in "(To) where are you sending that message", or more commonly "Where are you sending that message to". Dónde alone is correct because it doesn't mean you send yourself or something somewhere, it's just a place you'll be. "Where do you want to work?" Sounds a lot more normal than "To where do you want to work"