A proofreading testFalcontext against AI and the writing tools.

What it shows

• The AI tools catch the most. Claude caught all 28, Google’s AI Mode and Grammarly 27, ChatGPT 26.
• Falcontext caught 23 of 28 with no AI at all, on your own device, and not a single false alarm. That’s more than Word (21), Pages (20) and Google Docs (19), and fewer than ProWritingAid (24), Grammarly and the chatbots.
• False alarms. ChatGPT and Google’s AI Mode both “corrected” a sentence that was right (“no room in their attic”). ProWritingAid wanted to remove a correct “that that”, and Pages to change a correct “flat affect”.
• The hardest one: “Her apron was white with flower”. ChatGPT, ProWritingAid and Google Docs all suggested flowers; only Claude, Google’s AI Mode and Grammarly said flour.
• Energy. Falcontext’s whole analysis of a 115,000-word novel took about 0.0016 watt-hours on a MacBook Pro, measured. One AI read of a shorter book is estimated at around 40. More in the blog post.

Who missed what

• 1. their → there: caught by all nine
• 3. the the → the: caught by all nine
• 4. loose → lose: missed by Falcontext, Pages (Mac)
• 5. reign → rein: missed by Word (Mac), Google Docs
• 7. then → than: missed by Google AI Mode
• 9. peaked → piqued: missed by Pages (Mac)
• 10. flower → flour: missed by ChatGPT, ProWritingAid, Falcontext, Word (Mac), Pages (Mac), Google Docs
• 11. into into → into: caught by all nine
• 13. affect → effect: caught by all nine
• 14. baited → bated: missed by Google Docs
• 16. it's → its: caught by all nine
• 17. a a → a: missed by Pages (Mac)
• 18. except → accept: missed by Word (Mac)
• 19. warn → worn: missed by ProWritingAid, Falcontext, Word (Mac), Pages (Mac)
• 21. tow → toe: missed by Google Docs
• 23. weather → whether: caught by all nine
• 24. to to → to: caught by all nine
• 25. complimented → complemented: missed by Falcontext, Word (Mac), Pages (Mac), Google Docs
• 26. Their → They're: caught by all nine
• 28. pouring → poring: missed by Grammarly, Word (Mac), Pages (Mac), Google Docs
• 29. of of → of: caught by all nine
• 31. who's → whose: caught by all nine
• 32. to → too: caught by all nine
• 34. Bare → Bear: missed by Google Docs
• 35. would would → would: caught by all nine
• 36. wetting → whetting: missed by ChatGPT, Falcontext, Word (Mac), Pages (Mac), Google Docs
• 38. lose → loose: missed by ProWritingAid
• 40. principle → principal: missed by ProWritingAid, Google Docs

How I tested

• The sentences were written for this test, before any tool saw them: 22 with a sound-alike mistake, 6 with a doubled word, and 12 right ones, some written to tempt a checker into a false alarm. Sentences that echoed Falcontext’s own earlier test sets were rewritten, so it couldn’t have been tuned for them.
• Falcontext was scored first, before any other tool had seen the sentences.
• The chatbots each got the sentences in a new chat, with the standard model and this question, word for word: “Proofread these sentences. Some have a mistake, some don’t. For each sentence with a mistake, give its number, the wrong word and the correction. Only real errors, no style suggestions.”
• The writing tools got the sentences only. Their underlines were checked to see how many of the suggestions were right.
• Caught means the wrong word was found and the right correction given: “flower → flowers” doesn’t count. A false alarm is any change suggested to a right sentence. Style suggestions (such as ProWritingAid’s passive-voice notes or Grammarly’s “improve wording”) weren’t counted, just as Falcontext’s own style checks weren’t.
• One test, one day. These tools change, and 40 sentences can’t show everything a tool can do. ProWritingAid, Grammarly, Word, Pages and Google Docs check much more than sound-alikes and doubled words; so does Falcontext, with checks for fiction. This test is only about this kind of slip.

The 40 sentences

Try them in your own tool.

1. Mara dropped her wet boots right their, beside the coal scuttle. Sound-alike: their → there
2. The dog wagged its tail so hard that it knocked a cup off the table. Right: "its" is the correct possessive; a checker might suggest "it's".
3. "I told you we should have taken the the early train," Jonah muttered. Doubled word: the the
4. "If you keep pulling at that thread, you'll loose the whole button," Gran warned. Sound-alike: loose → lose
5. The old captain gave his first mate free reign over the ship while he slept. Sound-alike: reign → rein
6. "Who's brave enough to knock?" whispered Theo, staring at the iron gate. Right: who's = who is, correct
7. By fourteen, Ada stood a full inch taller then her father. Sound-alike: then → than
8. He had had enough of the noise by midnight, so he went out walking. Right: "had had" is a legitimate past perfect, not a doubled word.
9. The stranger's offer peaked my curiosity, though I knew better than to trust him. Sound-alike: peaked → piqued
10. Her apron was white with flower by the time the first loaves came out. Sound-alike: flower → flour
11. We walked along the river until the lights of the village came into into view. Doubled word: into into
12. The therapist noted the boy's flat affect and wrote a careful line in her file. Right: "affect" is correct as a psychology noun (emotional expression); a checker might suggest "effect".
13. Losing the farm had a lasting affect on the whole family. Sound-alike: affect → effect
14. The crowd stood in silence, every one of them with baited breath. Sound-alike: baited → bated
15. She said that that was the last time she would ever lend him money. Right: "that that" is legitimate (conjunction + pronoun), not a doubled word.
16. The fox slipped through the fence and disappeared into the woods with it's prize. Sound-alike: it's → its
17. Ellen opened the drawer and found a a bundle of letters tied with string. Doubled word: a a
18. "I'll except your apology when you mean it," said Clara, folding her arms. Sound-alike: except → accept
19. Rain dripped through the roof and pooled on the attic's warn floorboards. Sound-alike: warn → worn
20. "It's far too dark to keep going," said Owen, unrolling his blanket. Right: it's and too both correct
21. The general expected every soldier to tow the line without asking a single question. Sound-alike: tow → toe
22. The ice on the pond was thinner than they had thought, so they kept to the shore. Right: "than" is the correct comparison; a checker might confuse then/than.
23. It was hard to know weather the guard had heard them or not. Sound-alike: weather → whether
24. The children ran to the window to watch the snow, pressing their noses to to the glass. Doubled word: to to
25. The scarf she wore complimented the deep green of her eyes perfectly. Sound-alike: complimented → complemented
26. "Their not coming back tonight," said the innkeeper, locking the heavy door. Sound-alike: Their → They're
27. "Whose muddy footprints are these?" the housekeeper asked, frowning at the rug. Right: whose = possessive, correct
28. He spent the whole evening pouring over old maps, looking for the lost mine. Sound-alike: pouring → poring
29. I could hear him laughing long after most of of the guests had gone home. Doubled word: of of
30. The principal called the two boys into her office and closed the door. Right: "principal" (head of a school) is correct; a checker might suggest "principle".
31. Lena stopped and asked the nurse who's bag had been left beside the bed. Sound-alike: who's → whose
32. The kettle was to full, and water spat across the stove. Sound-alike: to → too
33. Nobody was allowed upstairs, so the twins whispered their plans aloud in the cellar. Right: allowed and aloud both correct
34. "Bare with me a moment," said the clerk, searching the shelves for the ledger. Sound-alike: Bare → Bear
35. Sam said he would would call before he left, but the phone never rang. Doubled word: would would
36. The smell of fresh bread wafted from the kitchen, wetting everyone's appetite. Sound-alike: wetting → whetting
37. The ship lay stationary in the fog, its sails hanging loose from the masts. Right: "stationary" (not moving), possessive "its" and "loose" are all correct; tempting for stationery, it's and lose.
38. Without a word of warning, the horse broke lose and bolted across the field. Sound-alike: lose → loose
39. "You're welcome to stay," said Ruth, "but there's no room in their attic." Right: "You're", "there's" and "their" are all correct; tempting for your/you're and their/there checks.
40. The general's principle concern was keeping his men alive through the winter. Sound-alike: principle → principal

ChatGPT, Claude, Google, Google Docs, Grammarly, ProWritingAid, Microsoft Word and Pages are trademarks of their owners; Falcontext has no connection with any of them. Tested on 7 October 2026 with the versions available that day.

Related