Free English Grammar Checker
Paste any English sentence, email, or paragraph and get an instant grammar check with clear explanations. The checker finds verb tense errors, subject–verb agreement mistakes, preposition slips, missing articles, and word-order problems — and tells you why each one is wrong, so the same mistake doesn't come back tomorrow.
100% free · No account or login needed
What This Free Grammar Checker Finds
- Verb tense errors — “She go to school yesterday” → “She went to school yesterday”
- Subject–verb agreement — “He don't know” → “He doesn't know”
- Preposition mistakes — “I'm good in English” → “I'm good at English”
- Article errors (a, an, the) — “I have car” → “I have a car”
- Word form and countability — “buyed a new books” → “bought some new books”
- Sentence structure and word order problems
How the Online Grammar Check Works
Paste or type your English text
Write a sentence, an email paragraph, or an essay excerpt. A few sentences to a few hundred words works best.
Click “Check Grammar”
The checker analyzes tenses, agreement, prepositions, articles, and word order in seconds — no sign-up and no credit card needed.
Read the why, not just the fix
Every correction comes with the grammar rule behind it, so you learn the pattern instead of memorizing the fix.
Example: Before and After
She go to school yesterday and buyed a new books.
She went to school yesterday and bought some new books.
Three errors caught at once: past tense (go → went), the irregular verb form (buyed → bought), and countable noun grammar (a new books → some new books). The checker shows the rule behind each fix, just like it will for your own sentences.
Grammar Checker FAQ
Is this English grammar checker really free?
Yes. You can check your grammar online free with no account, no login, and no credit card. A fair-use limit on the number of texts per hour keeps the service free for everyone.
Does it explain the grammar rule behind each correction?
Yes — that is the biggest difference from other free checkers. Each mistake shows the suggested fix, the rule that applies, and a short explanation written for English learners, so you stop repeating the same error.
What kinds of mistakes does it detect?
Verb tenses, subject–verb agreement, prepositions (in, on, at), articles (a, an, the), word forms, spelling, and basic sentence structure. It is tuned for the mistakes English learners actually make, not just native-speaker typos.
Can I use it on my phone?
Yes. The checker works in any modern browser on Windows, Mac, Android, and iPhone — nothing to install. If you want offline practice with the same AI explanations, the PromGee Windows app covers that.
Is my text stored or shared?
No. Your text is sent only to run the check and is not stored, shared, or used for advertising.