Please state in which country your phrase tends to be used, what the phrase is, and what it should be.
Example:
In America, recently came across “back-petal”, instead of back-pedal. Also, still hearing “for all intensive purposes” instead of “for all intents and purposes”.
I’m glad some people got my joke, but seriously, what is wrong with “on accident”?
Well I find it useful to think of “by accident” as the equivalent to “by way of an accident” the accident was the way that the thing happened; there is a causal relationship there. Compare that with “On accident”, well, what does it mean to be on an accident? It sounds like a great way to get your shoes dirty.
I love when people try to justify all the preposition use in grammar, like we don’t have countless examples of it being completely arbitrary. Like why don’t we “watch at” a movie like we look at a painting, much like listen to vs hear. Or why do verbs with similar meanings take different prepositions, like decide on vs opt for (vs choose without a prep).
If it’s commonly used one way, then using it another way carries another meaning.
If you normally “watch” a movie, then “watching at a movie” implies some more distance, detachment, like you’re pointed in the direction of the movie instead of the substance.
It’s these little things that can make language so fun to use creatively, but also really hard to learn as a second language. Because you can’t just learn a rule of usage, you have to learn the rule and then encounter and remember all the common exceptions.