It took me an agonizing weekend to internalilze the formal rules for question formation in English, and I'm a native speaker. It may not be the most creative way, but I make sure my students have the following rules (from Swan) in their notebooks:
-Aux before subject
-If there is no other auxiliary, use "do". "Do" is not used with other auxiliaries.
-After "do", verb goes in base form
-If "What", "which", or "who" or "whose" is the subject of the sentence, don't use "do"
Naturally I try to guide the students to the rules themselves by giving them real questions extracted from interview transcripts, then breaking them down by writing each word on a card and having them put the cards in order.
But if time is short, I won't hesitate to dictate the rules as rules. For many students, this is enough, and when they make mistakes in the future, I ask them to look at their rules and reformulate the question, and if this doesn't work to write out their question and see if it follows the rules.
Now, I see the OP is in a Romance language country. I'm in Italy, and I found a question in Italian, cosa causa un trauma cranico? which has two different answers, because there is no differentiation in Italian between subject and object questions. The question therefore translates either as "what causes a concussion?" or "what does a concussion cause?". It's a trick question from a driving test. I give them this question in Italian, let them think of an answer, and hopefully two different students come up with two different answers. I find this example helps to introduce the idea of subj/obj questions and at the end of the lesson I have them translate the two possible meanings of the Italian question.