I think questions with “how”, " why", “where” etc. tend to be open. An example for a closed question would be: “Do you use apps to learn a new language?”
Maybe you could argue about “what” and “who” questions, but I prefer uninteresting questions to be filtered out by votes instead of rules, anyway, so I don’t care.
Also, even a “bad” question can be saved by a good answer, e.g. a report on language learning apps.
I can assure you that my van and my basement are totally save! So come right in stranger.