Grammar Fixer

The Common Mistakes a Grammar Fixer Catches

Most writing errors are not exotic — they are a small set of the same slips, made under time pressure, that spell-checkers sail right past because every word is spelled correctly. Knowing the usual suspects helps you understand what this tool is fixing and makes you a sharper proofreader of its output. Here are the ones that trip up almost everyone.

The homophone traps

These are correctly spelled words used in the wrong place, so only meaning reveals the error. Its shows possession while it'smeans "it is." Their (possessive), there (place), and they're("they are") are constantly swapped, as are your and you're. A grammar model reads the surrounding sentence to pick the right one — something a dictionary check can never do.

Comma splices and run-on sentences

A comma splice joins two complete sentences with only a comma ("It was late, we went home"); a run-on joins them with nothing at all. The fix is a period, a semicolon, or a joining word like "so" or "because." These are among the most frequent corrections because the pause feelsright even when the punctuation is wrong.

Agreement and apostrophes

Subject–verb agreementslips when the subject and verb drift apart ("the box of files are heavy" should be "is heavy"). Apostrophescause the mirror-image errors of adding one to a simple plural ("photo's" for "photos") or dropping it from a possessive. Both are easy to miss on your own work because you read what you meant to write.

What an AI fixer does well — and its limits

For mechanics — grammar, punctuation, and clunky phrasing — an AI proofreader is fast and reliable, and the "explain the changes" option turns each fix into a mini lesson. What it cannot do is know your facts or your intent, so always give the corrected text a final read to confirm the meaning is still exactly what you wanted. It polishes how you say something; you stay in charge of what you say.