Free AI Grammar Checker for Writers

Catch real grammar errors without flattening a deliberately informal voice.

Most grammar checkers were built for business writing, which is why they are so exhausting to run over prose. They flag the sentence fragment you placed on purpose, the conjunction you opened with for rhythm, the preposition you left at the end because the alternative sounded stiff. After the twentieth false positive, you stop reading the suggestions.

This grammar checker is built the other way round. It assumes your text is meant to be colloquial, and it treats deliberate rule-bending as style rather than error. What it looks for is the mechanical mistakes that survive a dozen revisions because the eye slides over them: verb tenses that drift mid-paragraph, subject-verb disagreement inside a long clause, dangling modifiers, comma splices, pronouns whose antecedent went missing two sentences ago, and broken parallelism in a list.

Findings come back in two groups. Clear errors are unambiguous. Judgment calls are technically incorrect but plausibly intentional — flagged, with the ambiguity acknowledged, so you decide rather than the tool. And if the text is clean, it says so instead of manufacturing problems to look thorough.

How to use this checker

  1. Paste the passage or chapter you want checked into the text field below.
  2. Click Copy full prompt to clipboard — you get the grammar instructions and your text together, in one block.
  3. Paste that into ChatGPT, Claude, Gemini, or any other LLM.

Each issue comes back quoted, with the specific rule it breaks and a correction that preserves your meaning and tone. Where a fix could go more than one way, you get the options and a recommendation.

Analyze the following text for grammar errors, from obvious mistakes to subtle imperfections a careful editor would catch. Focus on: incorrect or inconsistent verb tenses, missing or wrong articles, subject-verb agreement errors, dangling or misplaced modifiers, comma splices, pronoun-antecedent issues, incorrect parallelism, and any other mechanical problems. This text is intended to be colloquial in tone. Minor rule-bending is acceptable when it clearly serves a stylistic purpose: intentional sentence fragments, starting sentences with conjunctions, ending sentences with prepositions, and similar informal choices should be left alone. Only flag a fragment if it genuinely reads as accidental or creates confusion. For each issue found, provide the quote itself in bold, a brief explanation of the specific grammar rule being broken, and a corrected version in italic that preserves the original meaning and tone. If a fix could go more than one way, note the options and recommend one. Group your findings into two sections: Clear Errors (unambiguous grammar mistakes) and Judgment Calls (technically incorrect but possibly intentional — flag these but acknowledge the ambiguity). If the text is clean, say so. Do not invent problems to seem thorough.

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