Free Sentence Corrector

Paste broken sentences — agreement errors, tense drift, dangling modifiers, fragments — and get them rebuilt into grammatically sound lines that keep your original meaning. Every repair arrives labeled, so you can see precisely what was wrong and not just what was changed.

Where spell checkers work letter-by-letter and punctuation tools work mark-by-mark, this one operates at the clause level: who did what, when it happened, and whether the verb agrees with the honest answer to that question.

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What This Tool Catches

Subject-verb agreement across distance
Catches verbs seduced by the nearest noun instead of the true subject: 'The list of approved items are attached' → 'is attached', plus the singular traps set by 'each', 'neither', 'everyone', and 'a number of' versus 'the number of'.
Tense consistency repair
Stabilizes narratives that slide from past into present mid-paragraph ('she walked in and says…'), fixes impossible stacks like 'would have went', and aligns conditional clauses with their main verbs.
Fragments and fused sentences
Completes dependent clauses stranded alone ('Because the data was incomplete.'), breaks apart fused runs written without any separator, and merges comma-linked shards into properly connected statements.
Dangling and misplaced modifiers
Reattaches opening phrases to the actor they describe: 'Walking to the station, the bus passed me' becomes a sentence where a person, not a bus, is doing the walking.
Faulty parallelism
Balances lists whose items don't match in form — 'she enjoys hiking, to swim, and cycling' becomes three gerunds — so series read with equal weight instead of lurching between structures.
Pronoun reference and case
Clarifies ambiguous 'it' and 'they' references when two possible nouns compete, and repairs case errors like 'between you and I' where the object form 'me' is required.

How It Works

1Paste a single sentence or a whole paragraph of suspect lines.
2Click Correct Sentences and receive the repaired versions.
3Read bracketed labels naming each fault: agreement, tense shift, fragment, dangling modifier, faulty parallelism, pronoun case.
4Compare before and after to confirm the fix preserved your meaning rather than replacing your thought.
5For lines you'd rather fix yourself, use the labels as a diagnosis, rewrite by hand, and re-run the tool to verify.

Honest Limitations

Rule-based correctors parse sentences with fixed grammars; they reliably flag short agreement misses but collapse on long subjects separated from their verbs, and they have no way to judge which noun a modifier truly attaches to. An AI corrector handles those meaning-level faults because it tracks who is doing what — but honesty requires admitting the flip side: it may smooth over an unusual construction that was actually valid, and it can't guarantee that citation-formatted or code-quoted passages survive byte-for-byte. Human editors remain stronger on ambiguity that depends on intent. Use this for fast clause-level diagnosis; keep a human for stakes-high nuance.

Diagnosis first, correction second

Each fix carries its fault name — agreement, tense shift, fragment, modifier attachment — turning every corrected line into a micro-lesson. Writers who see 'dangling modifier' flagged three times in one page learn to spot the pattern themselves, which is the only durable cure.

Corrections follow a minimal-intervention rule: the smallest change that makes the sentence grammatical wins. Your phrasing survives wherever grammar allows it to; reordering happens only when the fault lives in the structure itself.

Before

Each of the participants were given a schedule, and while the training runs smoothly last month, several sessions was cancelled because the trainer fall ill.

After

Each of the participants was given a schedule, and while the training ran smoothly last month, several sessions were cancelled because the trainer fell ill. [4 fixes: 'each' takes singular 'was'; 'runs' → 'ran' (past context); 'sessions were' plural agreement; 'fall' → 'fell']

Sample corrections returned

Pro Tips From Heavy Users

To test agreement, strip the phrase between subject and verb: 'The list (of approved items) is attached' — the bare bones never lie.
Decide your paragraph's tense in its first clause and treat every later verb as owing allegiance to that anchor.
Question every opening -ing phrase by asking who performs that action; if the answer isn't the next noun, you've dangled a modifier.
Fragments are legal in dialogue and punchy marketing copy — just place them deliberately, never accidentally.
One idea per sentence prevents most faults before they form; sprawling sentences breed disagreement and fused clauses alike.

Frequently Asked Questions

Does it rewrite my ideas or just repair the grammar?

Repair only. The minimal-intervention rule means wording stays put unless the fault itself lives in sentence structure, like a fragment needing a subject supplied.

Can I run my whole essay through at once?

Paragraph-scale chunks give the best labeled feedback. Whole documents process too, but per-paragraph runs make each diagnosis easier to trace back and learn from.

Will I learn why something was wrong?

Yes — every change is tagged with its fault category and a short reason, which is exactly the part worth reading if the same errors keep recurring.

Does it touch style issues like passive voice?

No. Passive constructions are grammatical and left alone here; this tool targets genuine faults such as disagreement, fragments, and unattached modifiers.

How is this different from a general grammar checker?

Scope. A grammar checker sweeps surface mechanics across a document; this one goes deeper on clause-level syntax — agreement across distance, modifier attachment, parallelism — sentence by sentence.

Is it useful for non-native speakers?

Especially so. Agreement and tense-selection errors are the most common L2 hurdles, and the labeled output doubles as targeted practice material.