Guide

From draft to polished — in four steps.

A guided walkthrough of the writing studio. Roughly thirty seconds end to end.

01

Paste or type your draft

Drop a draft into the writing studio. The grammar check runs as you type — no submit button, no loading spinner, no waiting for a server response. The Harper engine runs entirely in your browser, which is why checks appear in under a second on most drafts.

You can paste an email, a paragraph, a full essay, or a multi-section report. There is no character limit on the grammar checker. For very long documents, working section by section often produces more useful results because you can review each suggestion in context before moving to the next paragraph.

02

Review each suggestion individually

Each issue shows the flagged word or phrase, the suggested correction, and a single-line reason in plain English. Read the reason before accepting the change. Grammar suggestions are not always right for your specific sentence — the checker does not know your audience, your company style guide, or the exact register you are writing in.

Use Apply to accept the correction and move the flag to the next issue. Use Dismiss if the original wording fits your context better. Dismissing a suggestion does not penalize you or affect future checks — it simply removes that flag from the current session. If you are unsure about a suggestion, tap the linked grammar guide to read the underlying rule before deciding.

The most reliable workflow: accept clear spelling and punctuation corrections automatically, but read the reason for any grammar suggestion before applying it. Subject-verb agreement and comma suggestions are usually straightforward. Suggestions about sentence structure, passive voice, or word choice depend more on context and are worth evaluating individually.

03

Choose a tone for AI Polish

After handling the grammar flags, you can optionally use AI Polish to rewrite the full draft in a consistent tone. There are three options: Formal removes hedging language, tightens passive constructions, and replaces casual vocabulary with professional alternatives — useful for emails to clients or managers, job applications, and formal reports. Casual softens stiff phrasing, shortens sentences, and makes the writing sound more conversational — useful for social posts, messages to colleagues, or any content where approachability matters. Concise strips redundant phrases, collapses wordy constructions, and removes filler words without changing the meaning — useful when a word count or character limit applies.

AI Polish sends your draft to a rewriting service when you press the button. Sign-in is required for Polish because rewrites use server resources. The free plan includes a monthly quota; the draft is not used to retrain AI models on your personal text. If you do not need a full rewrite, skip this step — the grammar check alone often handles the issues that matter most.

04

Replace your draft or copy the result

Once AI Polish finishes, you can swap the original draft with the polished version in one click, or copy the polished text to paste into your own editor, email client, CMS, or document. The writing studio does not save your drafts — if you close the tab, both the original and the polished version are gone. Copy the version you want to keep before closing.

If the polished version changed something you wanted to keep, you can undo the replacement and start over with a different tone or with the grammar-checked version alone. The most common workflow is: run the grammar check, apply the clear corrections, then decide whether the draft needs a full AI rewrite or is ready to send as-is.

What it catches

Built for the errors that matter.

Spelling, grammar, punctuation, and style — each explained in a single line so you understand the fix, not just apply it.

Spelling
Typos, doubled letters, and high-frequency misspellings like "recieve" or "definately" caught before they reach your reader.
Grammar
Subject-verb agreement, tense slips, pronoun confusion, and run-on sentences — with a plain-English reason for every flag.
Punctuation
Missing commas, wrong apostrophes, stray spaces before punctuation, and unbalanced quotation marks.
Style
Wordy phrases, redundancy, and passive constructions where active reads better — so your writing is tighter, not just correct.
By document type

The checker works differently for each writing context.

Same tool, different priorities — here is how to get the most from it depending on what you are writing.

Professional emails
Run the grammar check before sending any email to a client, manager, or new contact. Pay particular attention to subject-verb agreement flags and apostrophe corrections, which are the errors that most often undermine credibility in professional correspondence. For tone, use the Formal AI Polish option to remove hedging phrases like "I was just wondering" and passive constructions like "it was decided that." A single polish pass typically shortens a business email by 15–25 percent without changing the message.
Academic essays and papers
Grammar check the full essay after drafting, not during. Checking mid-draft interrupts the writing flow and surfaces issues that may disappear during revision. After drafting, run the check, apply the clear mechanical corrections, and then review the sentence-level suggestions individually — academic writing has specific conventions around passive voice and formal vocabulary that differ from what a general grammar check expects. Use the grammar guides linked from suggestions to understand the underlying rule, not just accept the correction.
Reports and proposals
Work section by section in long documents. Paste each section separately, resolve the flags, then copy the corrected text back into your document. This produces more accurate results than pasting a full 3,000-word report at once, because you review each correction in its local context. For client-facing proposals, use the Formal AI Polish pass after handling the grammar flags — it removes the hedging and tentativeness that weakens persuasive writing.
Social content and web copy
Short-form content has less tolerance for mechanical errors because each sentence carries more weight. Run the check on headlines and opening lines first — these are the sentences readers use to decide whether to continue. For web copy, the Concise AI Polish tone removes filler phrases and redundant qualifiers that slow landing page copy down. For social captions, the Casual tone softens overly formal phrasing that reads awkwardly on a personal feed.
Understanding suggestions

Not every flag is a definitive correction.

Grammar is context-dependent. Here is how to read what the checker is telling you.

Spelling and repeated words
These are almost always right to accept. A misspelled word is a misspelled word, and a doubled word like "the the" is always an error. Accept these without reading the reason in detail — they are the highest-confidence corrections the checker makes.
Subject-verb agreement
Usually correct, but read the sentence before accepting. Some agreement flags involve collective nouns or complex sentence structures where the rule depends on whether you are treating a group as singular or plural. The linked grammar guide explains how to decide. If the sentence is unambiguously wrong, accept the correction. If it involves a deliberate stylistic choice, dismiss the flag.
Confused word pairs
Flags for confused pairs like affect/effect, its/it's, or their/there/they're are worth checking individually. The checker identifies these based on the word form present, but context determines which form is correct. Open the linked guide, read the decision rule, and verify that your intended meaning matches the suggested correction before applying it.
Style suggestions
Passive voice flags, wordiness suggestions, and sentence structure notes are the most context-dependent category. Passive voice is correct in scientific writing, formal legal text, and anywhere the actor is less important than the action. Dismiss style flags when the original wording was intentional and fits the audience. Accept them when the sentence is genuinely harder to read than it needs to be.
Grammar guides

When to read the guide instead of just applying the fix.

The checker fixes the sentence. The guide explains the rule so the same mistake does not appear in the next draft.

Recurring errors
If the same type of flag appears more than twice in a draft — multiple comma suggestions, several apostrophe corrections, repeated confused-word flags — read the corresponding grammar guide rather than applying the corrections one by one. Understanding the rule is faster than fixing the same mistake in ten places. The Learn section is organized by topic and each guide includes the decision rule, the most common mistake, and the exceptions.
Suggestions you disagree with
When a suggestion looks wrong for your sentence, the guide explains why the checker flagged it. If the guide confirms the checker is right and you are looking at an exception, you will understand the exception clearly enough to dismiss the flag with confidence. If the guide confirms your instinct, dismiss the flag and keep your original wording.
Rules you want to learn
The most efficient way to improve grammar over time is to read one guide per week on a rule you apply regularly but are not completely confident about. Good starting points: comma rules, subject-verb agreement, its vs. it's, affect vs. effect, and active vs. passive voice. Each takes about five minutes to read and applies to writing in nearly every context.
Before important submissions
Before a job application, a client proposal, or an academic submission, check the grammar and also review the guides for the two or three grammar rules you know you apply inconsistently. This combination — automated check plus conscious review of your known weak points — catches more errors than either approach alone.

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