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”.
Wouldn’t it be “ought not to”?
Why no! In the negative (ought not) you don’t need the to.
Neat. That gives me old British author vibes