How to Get Grammar Correction While Typing on Mac

Q: Why does Charm need Accessibility permission for grammar correction?

Charm uses the macOS Accessibility API to monitor and correct text across every app. This is the only system-level mechanism that allows a third-party tool to read and modify text in applications it does not own. Without this permission, Charm cannot see what you are typing in any app.

How-To April 2026 5 min read

macOS does not correct grammar while typing. It has spell check, but no engine that detects and fixes grammar errors automatically as you write. The solution is Charm, a native Mac app whose Polish feature corrects grammar at sentence end - while typing - in every application on your Mac. Setup takes under two minutes and requires one permission grant in System Settings.

Why doesn't Mac fix grammar while you type?

macOS includes a capable spell checker but its grammar tools are fundamentally reactive. The native grammar checker in NSSpellChecker flags errors with a green underline and waits for you to right-click and select a correction. It does not apply fixes automatically, and it only works in apps built with Apple's standard text frameworks.

macOS 15 Sequoia added Apple Intelligence Proofread - a more capable grammar engine - but it also requires manual invocation. You select text, right-click, and choose Writing Tools from the context menu. It is not grammar correction while typing; it is grammar correction on demand.

For grammar correction that actually fires while typing - before sentences reach their destination - you need a third-party tool. A 2023 survey found that 71% of Mac users believe their Mac corrects grammar automatically, but what they experience is spell check. The gap between spell check and grammar correction is significant: subject-verb disagreement, tense errors, homophone confusions, and comma splices all pass spell check because every word is correctly spelled.

Charm fills this gap with Polish, a grammar engine designed specifically for continuous, real-time correction while typing.

What is Polish and how does grammar correction while typing work?

Polish is Charm's grammar correction feature. It uses the macOS Accessibility API to monitor text across every app on your Mac and fires at natural sentence boundaries - when you type a period, question mark, or exclamation point.

At each sentence end, Polish analyses the completed sentence for grammar errors: subject-verb disagreement, wrong tense, homophone confusion, comma splices, missing articles, and fragment sentences. If an error is found, it corrects the sentence in-place and the affected text briefly glows blue - a visual confirmation that distinguishes grammar corrections from spelling corrections (cyan glow from Spells) and word predictions (purple from Oracle).

The correction happens while you are still typing, before the sentence reaches any recipient. In the time it takes you to type the next word, the grammar in the previous sentence has already been fixed.

All processing is on-device. Polish uses Core ML models that run locally on your Mac - no internet connection is required and nothing is sent to external servers. This matters for anyone writing about confidential or sensitive topics.

Step 1: Download Charm from theodorehq.com/charm

Go to theodorehq.com/charm and click Get Charm. Charm costs $9.99 as a one-time purchase - no subscription, no renewal, no account required. After completing the purchase, download the .dmg file.

Charm requires macOS 14 Sonoma or later. It runs on both Apple Silicon Macs (M1 and later) and Intel Macs. The download is small - under 15 MB - so it completes in seconds.

One-time purchase. $9.99 covers up to three Macs and includes all future updates. Grammarly Premium costs $144 per year - over three years, Charm costs 97% less for broader, system-wide coverage.

Step 2: Move Charm to Applications and open it

Open the downloaded .dmg file. A window appears with the Charm app icon and a shortcut to your Applications folder. Drag Charm.app into the Applications folder.

Once the copy completes, eject the disk image by right-clicking it in the Finder sidebar and selecting Eject. There is no installer wizard, no restart required, and no licence key to enter at this stage.

Open Charm from your Applications folder, or use Spotlight: press Cmd+Space, type "Charm", and press Return.

Step 3: Grant Accessibility permission in System Settings

On first launch, Charm will prompt you to grant Accessibility permission. This is the single permission that enables grammar correction while typing across every app on your Mac.

Charm needs Accessibility access because that is the only system-level mechanism on macOS that allows a tool to read and modify text in apps it does not own. Without it, no third-party app can correct grammar while typing in Mail, messaging apps, or any other native application.

When the prompt appears:

Click Open System Settings
Navigate to Privacy & Security > Accessibility
Find Charm in the list and toggle it to enabled
Enter your Mac password to confirm if prompted

The permission process takes about 20 seconds. Once granted, it never needs to be repeated.

Privacy note: Granting Accessibility permission does not mean your data is shared. Charm processes all text 100% on-device. Your keystrokes never leave your Mac. The permission enables local text monitoring and correction - nothing is transmitted externally.

Step 4: Click the menu bar icon and enable Polish

After granting permission, the Charm icon appears in your menu bar. Click it to open the Charm control panel.

You will see toggles for Charm's three features:

Spells (cyan) - spelling correction while typing. Fixes misspelled words in real time across every app.

Polish (blue) - grammar correction while typing. Corrects grammar errors at sentence end across every app. This is the feature to enable for grammar correction while typing.

Oracle (purple) - word prediction. Shows predicted words in grey text; press Tab to accept.

Toggle Polish to enabled. You can also enable Spells and Oracle if you want comprehensive correction while typing. Each feature can be turned on or off independently.

Step 5: Type naturally - grammar is corrected at sentence end

With Polish enabled, write in any Mac app as normal. When you end a sentence with a period, question mark, or exclamation point, Polish analyses the completed sentence and corrects any grammar errors in-place.

To verify it is working, try a deliberate grammar error. Type "She don't know the answer." and press period. Polish corrects it to "She doesn't know the answer." with a brief blue glow on the corrected text.

From this point, grammar correction while typing is active across your entire Mac - in every app, every text field, every context where you write. No per-app setup is needed, and no app needs to support grammar checking independently.

Research comparing real-time correction to post-edit review shows that real-time tools fix 3x more errors - because the correction happens at the moment of creation rather than relying on a separate review pass that writers often skip or miss errors in.

Optional: Disable grammar correction in specific apps

If you want Polish to leave a particular app untouched - a code editor where automatic correction would be disruptive, for example - you can exclude it in seconds.

Switch to the app you want to exclude
Click the Charm icon in the menu bar
Click "Disable for [App Name]"

Charm will leave that app entirely alone while continuing to correct grammar while typing in every other app. You can re-enable it at any time from the same menu.

For a broader look at what real-time grammar correction covers and how it compares to other approaches, see the complete guide to real-time grammar correction on Mac. For the direct answer to whether macOS includes any grammar correction, see does Mac have real-time grammar correction.

Get real-time grammar correction on your Mac

Charm fixes grammar as you type, in every app. One-time purchase. No subscription.

✓ Learn more about Charm ✓ Get Charm for Mac $9.99

Frequently asked questions

Does Mac have built-in grammar correction while typing?

No. macOS has spell check but no grammar correction while typing. The native grammar checker in NSSpellChecker requires manual right-click invocation and only works in apps built with Apple's standard text frameworks. For automatic grammar correction while typing in every Mac app, you need Charm's Polish feature.

Why does Charm need Accessibility permission for grammar correction?

Charm uses the macOS Accessibility API to monitor and modify text across every app. This is the only system-level mechanism that allows a third-party tool to correct text in applications it does not own. Without it, Charm cannot see or fix grammar in Mail, messaging apps, note tools, or any other app outside the browser.

When does Polish correct grammar while typing?

Polish fires at sentence boundaries - when you type a period, question mark, or exclamation point. It analyses the completed sentence and corrects any grammar errors in-place. The corrected text glows briefly blue as confirmation. This timing is deliberate: it avoids interrupting you mid-sentence while ensuring every sentence is corrected before you move on.

Does Charm correct grammar while typing in every app?

Yes. Because Charm uses the macOS Accessibility API rather than a browser extension or app-specific integration, Polish works in every Mac app where you type: email clients, messaging tools, document editors, note apps, code editors, and any form field in any application. One setup covers your entire Mac.

Can I use grammar correction while typing without a subscription?

Yes. Charm is a one-time $9.99 purchase with no subscription and no renewal. Grammar correction while typing is active permanently across every app on your Mac. No account is required, and no internet connection is needed after installation.