Here is my limited opinion. I am conversational level in Spanish and French and understand and can read very basic Italian. They say if you are a writer to write what you know. I'd say the same for domaining. For example I would say Night School but in Spanish that would be Instituto (school) del (of the) noche (night).
I have some Spanish, Spanglish and some words as domain hacks across the dot but get very little views.
Not a great success. Pure English names in dotcoms would appear to be the most straigtforward for me. Anything else would be more difficult with fewer end users.
K I S S makes sense in this instance.
I have never sold any other language domains so my opinion would be just that and not backed by any statistics or science.
You have been warned lol.
Regards,
Reddstagg