Question

I think the design is straightforward so no explanation is required.

Question: Is there a way to inditcate the language of the name column in courses table? Maybe to link it with the languages table?

Edit: Or maybe separate the name-language pare in another table with id and reference it in courses table?
Edit2: Course language and Name langauge may be different

Answer 1

Question: Is there a way to inditcate the language of the name column in courses table? Maybe to link it with the languages table?

There’s no need. The following query will give you what you want:

SELECT c.name, COALESCE(l.name,'default') as language
FROM courses c
LEFT JOIN courses_has_languages cl ON (cl.courses_course_id = c.course_id)
LEFT JOIN languages l ON (l.language_id = cl.languages_language_id)

Of source it would be even better if you just rename your column names so the query can be rewritten to:

SELECT c.name, COALESCE(l.name,'default') as language
FROM courses c
LEFT JOIN courses_has_languages cl ON (cl.course_id = c.id)
LEFT JOIN languages l ON (l.id = cl.language_id)

But that’s just my preference.