← All models Claude Sonnet 4.6 editing test Anthropic · Tested Oct 28, 2026 · 1m 44s · $0.10
Four checks All in one 49/90 caught
Grammar & spelling 32/45 Repetitions 4/15 Redundancy 6/15 Consistency 7/15 52 comments · 5 extra flags
Claude Sonnet 4.6's comments when asked for all 4 checks in one prompt on our 6,000-word test story, where it left it. Click a missed mistake to find it in the text. The checks come from icanwrite , a markdown editor for writers.
Missed · 41
who, not whom: subject of 'was' “whom she guessed was the owner” Misplaced modifier: bound nearly every “he had nearly bound every family Bible” 'along with' adds no subject: Mr. Pell … was “along with a secretary in a lace collar, were” 'The number' is singular: was “The number of entries in a good year were” Past habit: used to “the way he use to hold it up” any other shop: the bakery is on Wharf Street “longer than any shop on Wharf Street” Fragment: the survey has no verb “The survey from twelve years ago, which an engineer from the county” Missing auxiliary: had been “The fuse box by the back door been painted shut” Restrictive clause, no commas: the entries that held “The entries, which held only a single word, were” Past tense: led “Nora lead the way upstairs” in to, not into “turned his uniform into the quartermaster” an MBA: said 'em-bee-ay' “Daniel had a MBA” 'one of those who' takes a plural verb: were “one of the last binders in New England who was still” Distinctive, chapters apart: pewter “Pewter light from the tall back window” Close: silence … silent “The silence in the workshop” Distinctive, chapters apart: meticulous “His records were meticulous” Close: neatly … neat “neatly labeled” Distinctive, chapters apart: gleaming “a gleaming pair of shoes” Distinctive, chapters apart: sodden “carrying sodden leaves” Close: whispered … whispered “he whispered, as if it were a secret” Distinctive, chapters apart: brittle “a short, brittle sound” Distinctive, chapters apart: stubbornly “which stuck stubbornly” Close: remembered … memory “her hands remembered” Close: stiffness … stiff “some of the stiffness” twins are two “the two twins” one shrugs with the shoulders “shrugged his shoulders” the reason … was because “was because he had never paid himself” a sum is a total “The sum total” an agreement is mutual “By mutual agreement” a haven is safe “a safe haven” began is first “the week we first began” join together “wants them to join together” an outcome is final “The final outcome” The bakery has three tables; she sits at the fourth “three small tables” Said on Friday: the day after tomorrow is Sunday “On Friday a woman knocked” The ledger: green, then red “a ledger bound in green leather” Tea becomes coffee “poured her a mug of tea” The bakery: two doors down, then a ten-minute walk “BAKERY TWO DOORS DOWN” Nora's home: Chicago, then Boston “the firm in Chicago” Grandmother: Ruth, then Rose “her grandmother, Ruth” Writes left-handed, then with his right “He had been left-handed”