Final answer:
To correct the sentence, you could say, "Just know that I'm judging you when you use bad grammar."
Step-by-step explanation:
To correct the sentence, you could say, "Just know that I'm judging you when you use bad grammar." The original sentence has incorrect grammar by using "Im" instead of "I'm" and not capitalizing the word 'Just'. By making these corrections, the sentence becomes grammatically correct.
Learn more about correcting a sentence with bad grammar