Yes, something can happen every day for hours.
It's somewhat colloquial to say "the language school happens".
Better would be: language school classes happen every day for hours.
Classes then would be happening, and not the school.
Bear in mind that people often speak fast and are not paying attention to every little detail of their speech. This causes all sorts of phenomena such as this one to occur.
Here are some features of spontaneous speech:
Spontaneous speech contains a number of
phenomena that cause problems for current systems.
• filled pauses - noises made by the speaker that don't correspond to words (ah, uh, um, etc).
• restarts - repeating a word or phrase. The original word or phrase may be complete or truncated.
• interjections - extraneous phrases as in "on line thirty, I guess it is".
• unknown or mispronounced words
• ungrammatical constructions - Users make errors of agreement (sub-verb, number, etc) and may use constituents in unusual orders ("to the utilities cell add fifty dollars").
taken from Understanding Spontaneous Speech by Wayne Ward: