Murrica! No wonder Trump is the President.

Damn. That just makes me sad ):

I had a high school English teacher tell me that "mirth" isn't a word

Same everywhere ... proper spelling and grammar are a problem in just about any of the leading industrial nations. We've all gotten fat and lazy and can't be bothered to check the kids homework (or don't have time due to multiple jobs). And the approaches in some elementary schools, to write like you hear it, totally clash with what the kids are supposed to deliver later on in middle school and high school. (at least here in Germany)

"Ain't" is used since the 18th or 17th century. "Acrost" since the 18th century in various dialects. "Irregardless" is a hundred years old and part of the "American's don't speak the queen's English" nonsense, wich doesn't make it a correct usage, but it's not that bad. "Could of" (and iregardless and any kind of straight incorrect and stupid term, and wheadonspeak / buffyspeak) is acceptable in written speech or first person perspective as it's used by the character to show their personality, level of education etc. Also in satire. And people wonder why bookworm me hated lit teachers...

I blame social media. It's dumbing the minds of so many people, all the Internet shorthands.

Of all the idiotic aspects of English - the fact that "ain't" is not considered a word yet selfie is is absurd. For some reason a language such as English as a living construct that adapts and conforms yet somehow this word that has been in common usage for the last 100+ years isn't "a word". My ass.

The American education system is failing because kids don't care anymore and teachers make things about passing more than actually learning.

It's just going to get worse. With Betsy DeVos installed as the queen of education, you can expect formal essays to be peppered with emojis.

Of course writing skills have become terrible. They haven't taught spelling, writing or language silks to the prospective teachers in college since the 1960s. I remember pointing out spelling and sentence errors, written by the teacher, to my daughters teacher in middle school. She just laughed and said "oh that's not important". What the hell - yes it is if you're the English teacher!!