I've sent more emails than I'd like to admit where the tone was just wrong. Too casual for a client. Too stiff for a teammate. Full disclosure: I built BeLikeNative, a free Chrome extension for real-time grammar and writing help. Take my perspective accordingly.
Tone is one of those things that's invisible when it's right and painfully obvious when it's off. A "hey can you check this out?" works fine in Slack. Drop that into a proposal and it reads like you don't take the work seriously. The words carry the same meaning, but the impression changes completely.
What informal-to-formal conversion actually looks like
The shift from informal to formal writing usually comes down to a few patterns. Contractions get expanded. Phrasal verbs get replaced with single-word equivalents. Personal pronouns get pulled back. And sentence structure gets tightened up.
Here are some real examples I run into constantly:
