Ocaml learning app

Hello, I am creating a learning app to learn OCAML that is also going to have a chatbot inside. Therefore, it would help me a lot if you could write questions that you might have asked yourselves about ocaml while learning it. I learned ocaml at a university and we didn’t go through everything and I listed in the google forms all the topics that the questions can be about.

Example: What is complexity?

Thank you so much for your help !

Google forms: https://forms.gle/wavDquRZDRA1otus5