FeatureFeb 8, 20264 min read

Tone & Polish: Rewrite Any Email to Sound Exactly Right

Too aggressive? Too passive? Kerna's rewrite engine adjusts your tone, fixes grammar, and ensures every email lands exactly the way you intend.

You type a reply when frustrated. You read it back. It sounds angry. You soften it. Now it sounds passive-aggressive. You rewrite again. Twenty minutes later, you have three sentences.

Tone is the hardest part of written communication. Without vocal cues, every word carries outsized weight. Kerna's Tone & Polish feature takes the guesswork out of how your message will be received.

How Rewriting Works

Select any text in your compose window — a draft reply, a forwarded message, or a quick note — and click Rewrite. Kerna offers several transformation modes:

More Professional — Elevates casual language to business-appropriate register. Removes slang, tightens structure.

More Friendly — Softens formal language. Adds warmth without losing substance.

More Concise — Strips filler words, eliminates redundancy, and cuts to the core message. A 200-word paragraph becomes 80 words.

More Empathetic — Adjusts phrasing to acknowledge the reader's situation. Useful for difficult conversations, rejections, or sensitive feedback.

Grammar & Clarity — Fixes grammatical errors, improves sentence structure, and enhances readability without changing your intent.

The Non-Native Speaker Advantage

For professionals writing in a second language, Tone & Polish is transformative. You write naturally in your own style, and Kerna polishes it to native-level fluency. No awkward phrasing, no misused idioms, no grammatical artifacts that signal "this person is not a native speaker."

This is not about replacing your voice. It is about removing the barriers that prevent your expertise from being taken seriously.

Before & After

Before: *"We need talk about the budget problem. The numbers is not matching what we discussed. Please to fix this before Friday."*

After: *"I'd like to discuss the budget discrepancy. The current figures don't align with what we agreed upon. Could you please address this by Friday?"*

Same message. Same intent. Dramatically different perception.

Iterative Editing

Kerna does not force a single rewrite. You can run multiple passes — first tighten the structure, then adjust the tone, then polish the grammar. Each pass builds on the previous result.

Tone & Polish is available on Pro, Business, and Enterprise plans with GPT-5. This advanced editing feature is not included on Starter or Standard tiers. Upgrade to Pro to unlock the full suite: Compose, Extract, and Rewrite.

Tone & Polish: Rewrite Any Email to Sound Exactly Right — Kerna Blog | Kerna