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”.
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.