Muna school

What do you mean acceptable?

Who the hell are you to say how kids in another country should talk.

Language is mutable, it changes all the time, new words/phrases are coined all the time, existing words get new meanings or go out of use entirely.

You sound like the Earl of Lemongrab.

I have never heard that, but "going to" is sometimes shortened in casual speech.
Written - gonna "I'm gonna go to school." *
Spoken- pronounced more like "guna"
* Really, in that sentence, "go to" wouldn't be pronounced as two words. It would be blended to "gota" ("o" as in "go", same "a" sound as guna)

Ive heard "Imawna" school, a short for "Im on the way to school"
Its sorta like 'MAWMBACK" for "C'mon Back"
Its a deviation in pronunciation that I believe began at the start of the "truck driver CB radio voice" which became known as the ARKAHOMA dialect.

roger, 42

I'm glad you actually understood this question. Because I didn't. What ethnicity or slang does "muna school" allegedly come from?

I have no idea, but if that's what American kids want to say, fair enough. They're not hurting anyone.

Knowing the pronunciation might help work out the derivation. Is it pronounced moona or munna?

If the former it could be a contraction of moving now to school, but that's just a guess.

I’m right there with you tsar.
The closest I can think of if “I’m goin’ ta school”

So it must have sounded to Orister (if this was something he heard) like the “I” in “I’m” was dropped and the “goin’ ta” sounded like “una”

Sounds like someone who has a mouth full of mashed potatoes, who doesn’t have the sense to swallow before speaking.

you never heard the phrase 'Mawm back" or "Mom back" ?? Imawna school is a dialect that is super regional. Ive heard it all over the country.
"Cmawna my house a myee house, IMAWNA give you everything"--I forget who sang that but my mom would go around the house doing a pretty good cover.