Try this sentence in the MimicReader Writing Studio:
"She walked quickly into the room. The door was opened by her. A really really really long sentence about how she had been thinking about him for what felt like a thousand years but had never actually said anything out loud, partly because she was afraid and partly because she didn't know what to say."
Blue. Green. Yellow. Then red. The whole thing lights up like an X-ray.
"Quickly" gets a blue underline. "Was opened by her" gets a green one. The third sentence — sixty-two words long — sits on a faint yellow background that deepens to red as you cross thirty-five. You see your own habits laid out in colour. Most of the time you didn't know you had them.
The problem with post-hoc
The Hemingway Editor is a great tool. You paste your text in, it tells you what's wrong, you go back to your real editor and try to remember which sentence was the bad one. By the time you've made the fix, you've already written the next chapter the same way.
Post-hoc analysis doesn't change the habit. The habit forms at the keystroke. Feedback that arrives an hour later — after the chapter is done, after the scene is shaped — is just an audit. Useful, but slow.
MimicReader puts the lint in the editor. Same place you write. Same moment you type.
The four rules
Toggle Hemingway-style highlights in Settings (off by default — we don't force opinionated feedback on you). Then write. The Studio watches four things.
Adverbs — blue underline
Anything ending in -ly. Quickly. Suddenly. Really. Carefully. Most of them are filler. "She said quietly" wants to be "she whispered." "He ran fast" beats "he ran quickly." The underline isn't a verdict, it's a question: do you need this word?
Sometimes you do. Adverbs aren't illegal. But every blue underline is a chance to pick a stronger verb instead.
Passive voice — green underline
"The cake was eaten." By whom? Passive hides the actor. "She ate the cake" says who did what. Active prose has weight. Passive prose floats.
The Studio looks for was/were/been followed by a past participle. "Was opened." "Were eaten." "Have been told." Each one gets a green underline.
Sometimes passive is the right call — in dialogue, in technical writing, in scenes where the actor doesn't matter. But most of the time it's a wall between the reader and the action.
Long sentences — yellow, then red
Twenty-five words: faint yellow background. Thirty-five: faint red. Not a wall. A blush. The longer the sentence, the deeper the colour.
Hemingway didn't always write short. Faulkner wrote one sentence that ran a thousand words. The point isn't to forbid long sentences — it's to know you wrote one. Sometimes you'll keep it. Sometimes you'll see it and cut it in half. Either way, you'll have chosen on purpose.
Double spaces — subtle gray
You have them. Everyone does. Two spaces between sentences, three by accident, a tab where you meant a single space. The Studio greys them out so you can see what your fingers actually did. It's a small thing. It's also the kind of thing that survives all the way to a published EPUB if no one tells you about it.
The Polish problem
Most prose linters are English-only. Type in Polish and they sit there, blind. Hemingway Editor doesn't speak Polish. Grammarly's Polish coverage is partial. The handful of Polish editing tools that exist are heavyweight Word add-ins.
MimicReader has Polish rules built in. The Studio detects project.language = "pl" and switches the regex automatically.
- Adverbs in Polish — endings in -nie, -cko, -le, -wo. Szybko. Cicho. Naprawdę. Powoli. The Polish equivalent of -ly, with the same blue underline.
- Passive in Polish — był/została/zostało plus a participle. "Był otwarty." "Została zjedzona." Green underline.
- Long sentences — same thresholds. Polish sentences run longer naturally, but the warning still helps when one becomes unreadable.
It works because the regex uses the /u flag with an explicit Polish character class. Ąćęłńóśźż all match. The lint doesn't drop the second half of a word at the first diacritic, the way most English-trained tools do.
It's not a full linguistic parser. It's a heuristic. But for spotting the obvious habits — too many adverbs, too much passive — it's right more often than it's wrong, and it's the only thing of its kind that runs live in a writing editor, in Polish, that we know of.
Honest about heuristics
Regex doesn't understand context. "Only" ends in -ly and gets flagged as an adverb, but "only" is usually fine. "Was" followed by an adjective is not passive, but the regex sometimes thinks it is. "He was tired" might get a green underline. It shouldn't.
We don't pretend the rules are perfect. They're designed for awareness, not authority. The Studio shows you patterns. You decide whether the pattern matters in this sentence. Sometimes you'll keep every adverb on the page. That's fine. The point is that you saw them.
If you want the deeper kind of feedback — does this character read consistently, does the pacing work, is this scene earning its place — that's still your editor's job, or the AI Workshop's developmental tools. The live lint catches the prose-level habits. The structural stuff lives elsewhere.
Off by default
We didn't want to ambush new writers with red and yellow the first time they opened the editor. The toggle starts off. You turn it on when you want to be challenged.
Settings → Editor → Hemingway-style highlights. One click. Per-project. You can leave it on for a tight commercial draft and off for a freeform first pass. Some writers leave it off until revision and only turn it on for the second pass. Up to you.
Performance, honestly
The lint runs in a CodeMirror 6 ViewPlugin that adds Decoration.mark ranges to the visible text. The pass is debounced at 300 milliseconds — fast enough that you don't notice, slow enough that a 50,000-word manuscript doesn't lag while you type.
The regex pass only runs on the visible viewport. Scroll down, the highlights update for the new region. The full document isn't re-linted on every keystroke. That's how some editors choke on long manuscripts. We don't.
Not a grader
The Studio doesn't give you a score. It doesn't tell you your prose is "Grade 9" or that you should rewrite the paragraph. It shows you the patterns and trusts you to decide.
That's the difference between a tool and an authority. A grader tells you what to do. A mirror lets you see. The lint is a mirror. Quiet. Always on if you want it. Wrong sometimes. Useful most of the time.
Hemingway wrote with a typewriter and a pencil and a wastebasket. The wastebasket was the most important tool. We can't ship a wastebasket. But we can ship the moment of seeing — the moment before the bad sentence becomes the next bad sentence.
Turn on the mirror
Open the Writing Studio, flip the toggle, write a paragraph. Watch the colours. Decide what stays.
Open MimicReader