I consider the writers of Futurama to be on average smarter than what I would expect the average American to be, yet I’ve heard the professor say ‘ex cedra’. Yet they also use ‘axe’ instead of ‘ask’ so it may be on purpose.

Yanks don’t speak English

No one speaks standard English. The rules we follow when we write are almost meaningless when we speak. If you can be understood and you minimize ambiguity, language is serving its purpose.

Also really, you want to talk about “Yanks” and English? How many absurd dialects does the UK have in a landmass the size of Michigan? 😉

As far as “by accident” vs “on accident” goes, this is largely a regional difference, but it’s not like it changes the meaning. It likely comes from being the opposite of “on purpose” and, since linguistic rules should generally be descriptive rather than prescriptive (again, assuming it is understood and minimizes ambiguity), it’s perfectly cromulent.

The one that drives me insane is when people say, “I’m going to try and <verb>” instead of “try to <verb>.” I struggle with it syntactically, but since it has become such a widespread construction, I’m learning to accept the construction of the infinitive using “and” instead of “to.” Its origin makes sense to me, there are plenty of places in English where we combine verbs with “and,” (though in many of those cases we aren’t using the infinitive for the second verb). Like “go and clean your room” or “I will come and see.”

I accept this thing that is a violation of the rules of standard English I was taught because it’s widespread enough to be an accepted usage of the language. That’s how language works. They are not something handed down from on high, they are something people create over time, and they continually evolve.