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When you've been learning English all your life, you've been exposed to a lot of English, you can get by in many situatuions but you find yourself making the same mistakes over and over, even when a teacher, a friend, an online tutorial has told you that that is wrong.
- it's important to know that xxx is wrong. If you don't know you won't fix it
- you must become aware of it when you are about to say it / have just said it.
- remember the right way to say it (if you know / remember) and self-correct. and repeat-

it's important to make the association between the wrong and the right thing to say (whether it's pronounciation, a phrase, ...)- hear yourself say it right (aware that that's the equivalent to your xxx)  , so say it out loud, hear yourself say the word / phrase.

some things are hard to unlearn but by repeating it the right way, you're telling the brain to stop using the "old" wrong form.