Proper grammar enhances communication, while incorrect grammar and spelling can lead to confusion. For some audiences, bad grammar may reflect poorly on your attention to detail or intelligence. Unless you’re intentionally using “bad” grammar as a device to connect with the audience, you should generally avoid it. Be extra careful about mixing up homonyms, misspelling words, or creating ambiguous sentences. Don’t trust your ability to proofread your work without help. Use a grammar and spell-checker like Grammarly, which has a basic version that’s free of charge.