English writing help for non-native speakers

Correct isn’t the same as natural

If you learned English at school and now use it at work, you probably don’t make many mistakes a spell checker would catch. What gives you away is subtler: a phrase translated word for word, a preposition borrowed from your first language, a missing article, a request that sounds more formal or more blunt than you meant.

Your colleagues understand you. But a Slack thread with a US client or an email to your manager reads a little off, and you can feel it. So you reread every message, paste it into a translator to double-check, and a two-line reply takes ten minutes.

AI Grammatic is built for that gap. It fixes grammar and spelling like any checker, then goes further: it replaces literal translations, unnatural word choices and awkward word order with what a native speaker would actually write. Here’s what that looks like on sentences people really send.

What a rewrite changes, and what it leaves alone

Every rewrite fixes grammar, spelling, punctuation, capitalization, articles and prepositions. Then it looks at the sentence as a whole, the way an editor would, and rewrites the parts that are technically fine but sound translated.

It keeps your meaning, names, numbers, links, @mentions, emoji, formatting and line breaks. The result is about the same length as what you wrote. It doesn’t add greetings or sign-offs you didn’t write, it never uses em dashes, and it avoids the stock phrases that make text sound machine-written. A two-line Slack reply stays a two-line Slack reply, only now it reads the way a native speaker would write it.

You can try it on a sentence of your own in the live demo on the homepage, no download needed.

Write it in your own language, get natural English

Sometimes the fastest way to write good English is to skip English for a moment. Write the thought in Russian, Spanish, German or any of more than 30 languages, select it and press your English shortcut. You get what a native speaker would say, not a word-for-word translation.

This helps most when the topic is delicate, when you’re tired at the end of the day, or when you know exactly what you want to say in your own language and just can’t find the English for it.

Casual for Slack, formal for your manager

Getting the register right is one of the hardest parts of writing in a second language. Textbook English is often too formal for chat, and once you relax, it can come out too blunt. In AI Grammatic every language has two tones: press ⌘⌥E for casual, and add ⇧ for formal.

Not sure which one a message needs? Our guide to casual vs formal English has the rules of thumb, with examples from Slack and email.

How it works

1. Write as usual, in Slack, Mail, Gmail, Outlook, Notion, Teams, a browser or any other app.
2. Select the text and press ⌘⌥E. Add ⇧ for the formal version.
3. About a second later, the text is replaced in place. If you liked your version better, ⌘Z brings it back. It’s a normal paste, so undo works the way it always does.

Each language gets its own shortcut: your default language plus up to five more. You might keep English (US) on ⌘⌥E, put English (UK) on another key for the client in London, and German on a third for the team in Munich. Write in any language, press the shortcut for the one you want out.

AI Grammatic runs from the menu bar on macOS 14 or later. It’s a direct download, signed and notarized by Apple. It isn’t on the App Store because rewriting text inside other apps needs macOS Accessibility access, which the App Store doesn’t allow.

Make it sound like you

Native doesn’t have to mean generic. In Settings you can choose a rewrite style (neutral, professional, casual or concise) and add your own writing instructions, up to 500 characters, on every plan. For example:

• “Use British spelling.”
• “Keep technical terms in English.”
• “I write to clients in finance. Keep the tone calm and precise.”

There’s also a “No dashes” option, and on the paid plans you choose which AI model does the rewriting.

Will it help me learn?

It’s not a course, and it doesn’t pretend to be one. But you see your own sentence turn into the native version many times a day, and that adds up. You start to notice your patterns (for many people it’s articles, or “until” where English wants “by”) and catch them before you press the shortcut.

If you want those patterns spelled out, we wrote guides to the most common English mistakes for Russian speakers, Spanish speakers and German speakers. More are in the guides.

What it costs and where your text goes

Free gives you 10 rewrites a day with every language and both tones. No account, no API key. Premium is $69 a year (€59 in the EU): we run the AI, you get 50,000 words a day, and you pick the model from OpenAI, Claude, Gemini or DeepSeek. Pro is $29 a year with your own API key and no limit. See pricing for the details.

On Free and Premium, your text passes through our server to the AI provider and is discarded once the rewrite comes back. We keep daily usage counts, never your text. On Pro, it goes straight from your Mac to your own AI provider account. More in how we handle your text.