Since this is for ILT courses, I think you will need to either create 1 course for each language in their respective catalogues. If you pin it all to a single course you would only be bale to differentiate the language in your session names/descriptions which could be confusing to your users. Would be great if we could place only the sessions in catalogues but sadly we cannot.

Ended up doing the reverse of here, started with separate courses and the complaint was folks got lost over where to go since not everything was in language (also had many users who could use multiple languages and wanted to be able to “shop” for the best session based on date/time not language) Ended up going the one course, distinguishing by sessions, the names all start with the in language if they are not english so “Spanish - Normal Course Name Here”, which is controlled through programmatic scheduling so the structure is always there. Also important note that helped out here was I did a custom calendar interface which is how most register for sessions anyways, on there the name distinguishes but also color code in language vs. not, selecting the session brings them straight to the right session to register. All that said, from talking this kind of thing through with a few orgs now, it seems very company cultural specific for best choice.