A person never knows when they might misuse it. Avoid run-on sentences they are hard to read. No sentence fragments. It behooves us to avoid archaisms. Do not use no double negatives.
Verbs has to agree with their subjects.
Avoid trendy locutions that should flaky. Beware of jargon. If you are not cognitively aware of the nature of jargon, let's interface about it sometime. The passive voice should be avoided. Otherwise, your meaning may be understood by you will not know by whom.