Doubts concerning Memrise, Clozemaster, Duolingo.

[indeclinable]

I don't use any of those programs or similar but I was wondering if it's possible to create and customise a course. I'm particularly interested in making exercises (multiple option, filling the missing word, identifying synonyms, converting phrases from active to passive voice and vice versa, completing paradigms)... the one thing I do not want to do is the typical vocabulary exercises where you have to select the correct meaning. Is it possible to do so with any of the programs mentioned above or any other similar software?

[galaxyrocker]

Anki is probably what you want. It's by far the most customizable of the programs, and has a lot of plugins and stuff already made for it.

[jstan]

I'm pretty sure that you'd be able to do what you have in mind with either Anki or Memrise. I use and have built custom decks in both and think that they are both great tools. I agree with galaxyrocker that Anki is the most customizable/flexible, but personally prefer Memrise's more gameified interface.