Most AI writing help is editing
When people use AI for writing, they mostly bring their own words. “How People Use ChatGPT”, a working paper published by the National Bureau of Economic Research in September 2025, classified a sample of consumer ChatGPT conversations. Its authors, researchers at OpenAI and two universities, found that writing was the most common use at work, at 40% of work-related messages on average in June 2025. About two-thirds of all writing messages asked ChatGPT to “modify user text”, an edit or a translation for example, rather than to create new text from scratch (page 2 of the paper).
Editing carries a risk that drafting does not. When an AI writes a draft for you, you read it as new text and check it. When it edits your own words, you already know what they say, so it is easy to skim the new version and see what you expect to see.
The changes that slip through
An AI edits for flow. It cannot know which of your details are fixed, so a smoother sentence can come back holding a different fact. Here is a short email with two small grammar slips, written by someone whose first language is not English. We made up the email and both edits of it to show the pattern.
Hi Dana, Thank you for send the draft agenda. The venue said we can have the room from 9am on Thursday, March 12. It fits about 40 people, so we should not invite more than that. I asked Priya to bring the projector. Catering costs $650, and we may need to pay extra for coffee in afternoon. Best, Sam
Hi Dana, Thank you for sending the draft agenda. The venue said we can have the room from 9am on Thursday, March 12. It fits about 40 people, so we should not invite more than that. I asked Priya to bring the projector. Catering costs $650, and we may need to pay extra for coffee in the afternoon. Best, Sam Changes 1. "for send" became "for sending" (grammar). 2. "in afternoon" became "in the afternoon" (grammar).
Hi Dana, Thank you for sharing the draft agenda. I have confirmed with the venue that the room is available from 9am to 5pm on Thursday, March 13. It holds 40 people, so we must not invite more than that. The projector has been arranged. Catering costs $650, and we may need to pay extra for afternoon coffee. I am confident the event will be a great success. Best regards, Sam
What changed. The light edit fixed the two slips and left every other word alone. The full rewrite sounds more polished, and it changed six things Dana will act on. We put one of each kind into a single email, so do not expect all six in one real rewrite.
- A date moved. March 12 became March 13.
- A detail was added. Sam never wrote “to 5pm”. The AI filled a gap.
- “About” was removed. “About 40 people” became “40 people”, which reads like a counted figure.
- “Should” became “must”. Advice turned into a rule.
- A name was dropped. Priya is gone, and with her the answer to who brings the projector.
- A closing sentence appeared. Sam did not promise a great success.
Each one is a single word or figure, which is why it survives a quick read. We ran both edits through Edit Check: it lists all six points for the full rewrite, and for the light edit it reports that no detail changed.
“I am available from June 2, as my current contract ends on May 29.”
Not quite. Shorter, with both dates intact, and “from June 2” still rules out an earlier start. Edit Check flags the missing “not” so you can look, and this is a change to keep.
“My current contract ends on May 29, so I can start on June 2 but not before.”
Not quite. The order of the sentence changed and nothing else did.
“I can start as soon as my current contract ends on May 29.”
Yes. June 2 is gone, and “as soon as” now suggests you could start the next day. Whoever plans your first day has the wrong date. Edit Check lists June 2 as missing.
“I can start on 2 June, but not before, because my current contract ends on 29 May.”
Not quite. Only the way the dates are written changed. Edit Check reads June 2 and 2 June as the same date.
A flag marks where to look. You decide whether the change matters.
Ask for a light edit
What comes back depends on what you asked for. “Make this better” gives the AI permission to rewrite. For a light edit, say what may change and what must stay, then ask for a list of every change so you have something to check.
3/10 Needs work
- Has: What to make
- Missing: Who it's for
- Has: Background facts
- Missing: Length
- Missing: Format
- Missing: What to avoid
- Has: What good looks like
- Missing: An example
- Missing: If unsure
- Missing: Layout
Say who will read it, which details must stay exactly as written, the format you want back, and what the AI should do if a sentence is unclear. The score is worked out in your browser, and nothing is sent anywhere. Open in the Prompt Grader
Here is a request you can copy. Fill in the blanks in double braces.
Edit my text below for grammar and clarity only. It is {{kind_of_text}} for {{reader}}, and it has to stay in my own words.
"""
{{your_text}}
"""
Rules:
- Keep every number, date, time, name, quote and link exactly as I wrote it.
- Keep the words that show how sure I am, such as about, roughly, may and should.
- Do not add a fact, a sentence, a greeting or a closing line that is not in my text.
- Change as few words as you can, and keep my sentences in the order I wrote them.
Length: about the same as mine.
Format: the edited text first. Under it, a numbered list headed "Changes", with one line for each change, like this: "for send" became "for sending" (grammar).
A good edit reads as if I wrote it on a careful day.
If a sentence is unclear, or a detail looks wrong, do not fix it by guessing. Leave it as it is and ask me about it under the list.
The last lines matter as much as the rules. The list of changes is written by the same AI that made them, so treat it as a claim to check and not as proof. An AI that is allowed to ask a question does not have to guess what an unclear sentence meant.
If you would rather answer questions than write a request, the Prompt Builder makes one from a few plain answers. For specialist text that has to become readable, the plain language rewrite template carries the same rule: keep every fact, number, date, condition and exception.
Check the result in two minutes
A moved date is hard to see by eye, because you read what you expect. Let rules do the looking. Edit Check compares your text with the AI’s version in your browser, with no AI and no upload.
- 0–15 sPaste both versionsYour own text in one box, the AI’s version in the other.
- 15–60 sRead the listChanged and added details come first.
- 60–80 sKeep or put backPress Keep the change on what you accept, and copy the prompt for the rest.
- 80–120 sRead the new version onceFor sense, which rules cannot judge.
Timings are a guide for a text of about one page.
The list starts with what a reader is most likely to act on: a number, an amount, a date, a day, a time, a name, a quote or a link that changed or was added. Next come details that went missing and numbers that lost a word such as “about” or “up to”. The list also points at sentences that got firmer or softer, at a “not” that came or went, and at sentences you did not write.
Under the list, a word-by-word comparison shows everything that was taken out or put in, so a single swapped word is visible there even when the list says nothing about it. The check reads “March 14” and “14 March” as the same date and “five” and “5” as the same number, so a change of format is not reported as a change of fact.
Then read the new version once, from start to finish. Rules compare details and cannot judge meaning. A rewrite can keep every number and still shift what a sentence says, and the check can flag a change that is harmless. It can also miss a name. Names are found by their capital letters, so one written in lowercase goes unseen, and so can a one-word name that only ever opens a sentence. Month and weekday names are read in English only, and so are words such as “about” and “must”.
Keep a change, or put it back
Not every change is a mistake. Sometimes the AI caught one of yours. Keep a change when:
- It corrected a real error, such as a misspelled name, and you have confirmed that against the source and not against the AI.
- You asked for a shorter text and the dropped detail is one your reader does not need.
Have it put back when:
- A number, date, name or quote differs from what you wrote, and yours was right.
- A careful word is gone and you were careful on purpose: “about” because you had not counted, “should” because it is advice.
- The text now says something you did not say, however reasonable it sounds.
- A “not” came or went, and the two sentences no longer mean the same.
In Edit Check, press Keep the change on the first kind and those items leave the correction prompt. The prompt that remains names each point still on your list and asks the AI for those corrections only, leaving the rest of its version alone. Naming the points matters: a general request to “fix the facts” gives the AI nothing to check against.
When the text is final, the Copy Cleaner pastes it into your email or document without the stray asterisks a chat window can leave behind. If the text is not yours at all, and what you were handed is a summary of it, the check is a different one: see how to check an AI summary against the original.
If English is your second language
Fixing grammar is a fair job to hand to an AI. The trouble starts with the next request: “make it sound native” or “make it more professional”. That asks for a rewrite. The AI replaces whole sentences with standard ones, and every replaced sentence is a chance for a detail to change and for your own way of writing to disappear.
Ask for corrections only, with the reason for each. The reasons make the changes quick to check, and you learn from them.
Correct only the grammar and spelling mistakes in my text below. I am writing in my second language, and I want to keep my own words.
"""
{{your_text}}
"""
Do not replace a correct word with a more formal one, and do not join or split my sentences. Keep every number, date, time and name exactly as written.
Format: the corrected text, then a numbered list with one line for each correction and the reason for it, like this: "for send" became "for sending" (after "for", the verb ends in -ing).
If you cannot tell what a sentence means, do not rewrite it. Ask me.
- Keep your own sentences. Short, plain sentences are good English at work and in study.
- Watch the polite words. English softens a request with words such as “could” and “might”, and an edit can turn a soft request into a firm one. When Edit Check finds that, it labels the sentence “Firmer than you wrote”.
- Ask about a sentence that came back different. “Explain the difference in meaning between my sentence and yours” is a fair question, and the answer tells you which one to keep.
- Keep your voice. The guide to writing emails with AI shows how one past email of yours teaches the AI how you write. If an edit comes back sounding like everyone else, the Robot-Speak Checker marks the stock phrases, and the list of AI words to avoid explains them.
Key takeaways
- Most AI help with writing is editing text you already wrote, so the habit worth having is checking what changed.
- Compare the details first: numbers, dates, names and quotes. Then the words that carry certainty, such as “about” and “should”.
- Ask for a light edit: grammar and clarity only, every detail kept, nothing added, each change listed.
- Keep a change when the AI fixed a real error you have confirmed. Have the rest put back, point by point.
- Rules compare details and cannot judge meaning, so read the new version once yourself.
Questions
How do I see what ChatGPT changed in my text?
Ask it to list every change it made, then check that list yourself, because the same AI wrote it. Put your original and the new version side by side and compare the numbers, dates, names and quotes first. Edit Check does that comparison in your browser and shows every word that was taken out or put in.
How do I stop ChatGPT from rewriting everything when I only want proofreading?
Say what may change and what may not. Ask for grammar and clarity fixes only, with every number, date, name and quote kept exactly, no new sentences and as few changed words as possible. Then ask for a numbered list of the changes. The Prompt Builder can put a request like this together from a few plain answers.
Is it allowed to use AI to fix my grammar?
That depends on who is reading. At work, your employer’s AI policy decides. For coursework, your teacher or the course rules decide, and they may ask you to say what you used. A light edit that keeps your own words is the easiest kind of help to explain. Keep your original draft and the list of changes, so you can show what was yours.
Does Edit Check upload my text?
No. Both versions are compared by rules in your browser, with no AI involved, and nothing you paste is sent to thinkhard.si. The two texts are kept in that browser so they survive a reload, and the Clear both button removes them. The correction prompt reaches an AI only when you copy it there or press a button that opens it in ChatGPT or Claude.
The AI changed something and I think it was right. What now?
Keep it, once you have checked it against the real source, such as your calendar or the invoice, and not against the AI. An edit can catch a misspelled name or a date that does not match its weekday. In Edit Check, press Keep the change, and that item leaves both the count and the correction prompt.
Prompts to use with this
- Compare two lists in a spreadsheet and find what is missing or changedYou have two lists, such as last month's and this month's customers or a system export and your own tracker, and need what is in one but not the other and what changed.