Grammar and spelling errors undermine credibility faster than almost any other writing flaw. A typo in a job application, a grammatical error in a client proposal, a misspelled word in a social media post — these mistakes are easy to make and easy to miss on your own. Free online grammar checkers catch what your eye skips over.
What do online grammar checkers actually check?
Modern AI grammar checkers go far beyond basic spell-checking. A good tool checks:
- Spelling — Including words that are correctly spelled but used in the wrong context (their/there/they're, affect/effect, its/it's).
- Grammar — Subject-verb agreement, incorrect tenses, misplaced modifiers, run-on sentences, and sentence fragments.
- Punctuation — Missing or misplaced commas, incorrect apostrophe use, inconsistent quotation mark style, and serial comma consistency.
- Style and clarity — Overly long sentences, passive voice overuse, redundant phrases, and wordiness.
- Vocabulary enhancement — Suggestions for more precise or varied word choices when a word is repeated too often.
Grammar checker vs spell checker: what is the difference?
A spell checker catches words that do not exist in its dictionary. A grammar checker understands context and catches errors a spell checker completely misses:
- “Their going to the store” — No spelling errors, but “their” should be “they're.” Grammar checker catches it; spell checker does not.
- “I seen the movie” — All words spelled correctly, but grammatically wrong. Should be “I saw the movie.”
- “The team are working on it” vs “The team is working on it” — Both are technically acceptable depending on UK or US English, but a grammar checker with regional settings handles this correctly.
Step-by-step: checking grammar with ToolsGravity
- Open the AI Grammar Checker and paste or type your text.
- Select your language variant if available (US English, UK English, Australian English — these differ in spelling conventions for words like colour/color, realise/realize).
- Click Check Grammar. The tool highlights errors in the text and provides explanations and suggested corrections.
- Review each suggestion before accepting it. Context matters — the AI sometimes “corrects” correct text, particularly with technical jargon, brand names, or deliberate stylistic choices.
- Accept the corrections you agree with and manually handle the ones you do not.
- Run the corrected text through a final readthrough yourself. Grammar checkers catch errors but cannot judge whether your writing is clear and engaging.
Common grammar errors and how to fix them
| Error type | Example (wrong) | Corrected |
|---|
| Homophone confusion | The affect was immediate. | The effect was immediate. |
| Apostrophe misuse | The company revised it's policy. | The company revised its policy. |
| Subject-verb disagreement | The data shows different results. | The data show different results. (formal) |
| Dangling modifier | Walking to the office, the rain started. | Walking to the office, I noticed the rain starting. |
| Run-on sentence | I finished the report it was submitted. | I finished the report and submitted it. |
| Double negative | I don't have no idea. | I have no idea. / I don't have any idea. |
Tips for getting the most out of a grammar checker
- Do your first draft without the checker. Writing with a grammar checker open causes over-reliance — you start writing for the tool rather than for your reader. Write freely first, then check.
- Check in sections for long documents. Pasting 5,000 words at once may produce too many suggestions to review carefully. Check in logical sections.
- Add your brand and technical terms to a custom dictionary if the tool supports it, so they are not flagged as errors.
- Combine with a paraphraser. If the checker flags a sentence as complex or hard to read, the AI Paraphraser can suggest a simpler rewrite.
Summary
A good grammar checker is an essential writing tool, not a crutch. It catches the errors your brain skips over because it reads what you intended, not what you wrote. Use the ToolsGravity AI Grammar Checker as the last step before finalising any document that represents you or your organisation — always reviewing suggestions rather than accepting them blindly.