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Grammar Checker

A grammar checker scans text for spelling errors, common grammatical mistakes (subject-verb agreement, comma splices, dangling modifiers), punctuation issues, and style problems (passive voice, weak verbs, redundant phrases) — surfacing each issue with an inline highlight and a plain-English explanation of the rule. The ZTools Grammar Checker uses a curated English rule set, runs entirely in your browser (no text sent to a server), shows fixes you can accept with one click, and explains the why so writers learn the rule rather than blindly accepting suggestions.

Use cases​

Proofreading emails and business writing​

Catch the "their/there/they're" before it goes to a client. Confirm subject-verb agreement in long sentences. The 30-second pre-send check saves the embarrassing follow-up.

Essay and academic writing review​

Students paste a draft, see grammar issues highlighted, and get explanations they can learn from. Different from a spell-checker — catches structural and style issues too.

ESL learners checking idiomatic usage​

Learners catch "make a homework" → "do homework", "I am agree" → "I agree". The explanations help build internalized rules rather than just one-off fixes.

Tightening blog posts before publishing​

Style mode flags passive voice, weak verbs, "very" overuse, and redundant phrasing. Lets writers tighten prose before hitting publish.

How it works​

  1. Paste or type your text — Any length. The checker re-scans on edits with a debounce so it doesn't lag while typing.
  2. Pick the strictness level — Basic: spelling + clear grammar errors only. Standard: + punctuation and style issues. Strict: + advanced style (passive voice, wordiness, jargon).
  3. Read inline highlights — Each issue is underlined in color (red = error, yellow = warning, blue = style). Hover or tap for the rule explanation and suggested fix.
  4. Accept or reject each fix — One-click apply for any suggestion. Skip ones that don't fit your voice. Total error count drops as you accept.
  5. Read the final cleaned text — Once all issues are addressed, copy the polished output. Original is preserved if you want to compare.

Examples​

Input: "Their going to the store."

Output: Error: "Their" → "They're" (contraction of "they are").

Input: "The team are winning their match."

Output: Standard: "team are" → "team is" (collective noun, US English). British usage allows "are".

Input: "It is very, very important."

Output: Style: "very, very" → consider a stronger word (e.g., "critical", "essential").

Frequently asked questions​

How accurate is the grammar checker?

Catches ~85% of common errors with high precision. Misses subtle stylistic issues that depend on context. Doesn't replace a human editor — it's a first-pass safety net.

Does it support American or British English?

Both — pick the variant in the settings. Default is American. Switching between affects spelling (color/colour, organize/organise) and some grammar rules (collective noun agreement).

Will it suggest stylistic improvements?

Yes, in standard or strict mode. Flags passive voice, wordy phrases ("in order to" → "to"), weak verbs ("make a decision" → "decide"), and overuse of intensifiers ("very", "really").

Does it learn from my writing?

No — there's no model that updates per user. Stick the same rules apply to everyone. Future versions could add personal dictionaries (allow-listing brand-specific terms), but that's not active here.

Is my text sent to a server?

No — all checking runs in your browser. Important for confidential drafts, NDAs, and proprietary writing. The tool works offline once loaded.

Tips​

  • Always read the explanation before accepting — sometimes the "fix" doesn't fit your voice or the rule has a context-specific exception.
  • For long documents, fix in passes: spelling first, then grammar, then style. Mixing creates whiplash.
  • Style suggestions are aggressive in strict mode; if you write conversationally, standard is usually right.
  • A grammar checker plus a human editor beats either alone — the checker handles routine errors so the editor focuses on substance.

Try it now​

The full Grammar Checker runs in your browser at https://ztools.zaions.com/tools/grammar-checker — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub