Is there any difference between the usage of "in" or "on" in terms of class?
I'm teaching a class in/on math(s). My father teaches a class in/on marine biology.
I have a class in French to go to tomorrow. I have a class on historical artwork that I love.
I take a class in physics. I'm not taking any classes on Spanish history this year.
The difference seems minimal, but it also seems to exist. For instance, "I'm not taking any classes on Spanish" sounds odd to me, as if to say you could take classes on Spanish as a whole language, and not as a student of the language, if that makes any sense.
Anyone have any idea what's going on with these two prepositions?