¶ The Library

Common Errors

Landed with a red mark and no idea which cluster of errors you're in — start here

Curated by Roger Fielding 23 articles

Adults UK & US

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In this pillar

Every article, one shelf

Start here The Walk-In Clinic 4 min read Why that red mark is a symptom, not a failing — and here's the map to your fix

Affect/Effect, Accept/Except, Principle/Principal 9 min read Circle after circle round "affect", or maybe "effect" — the three pairs that trip everyone up
Commas, Semicolons & Colons — Fast Triage 11 min read Little circles that aren't about spelling at all — matching every comma, semicolon and colon to its job
Fragments, Run-Ons & Comma Splices 11 min read Half a sentence circled in red, or a colleague's report missing every full stop — three fast fixes
Its/It's, Their/There, Your/You're, Then/Than 9 min read A pink circle round "it's" changed to "its" — the four mix-ups everyone makes, sorted for good
Punctuation, Style & Myths — Which Problem? 2 min read Squiggle from the checker, and no clue if it's punctuation, style, or a myth — find your problem
Sentence-Level Trouble — Which Problem? 2 min read You've read the sentence back three times and it still doesn't sit right — find what's actually wrong
Some/Any/Much/Many/Fewer/Less 12 min read Red pen round "less" when you meant "fewer" — the busy pairs finally sorted for good
The Grammar Myths Clinic (Split Infinitives &c.) 12 min read Your teacher circled 'to boldly go' in red — turns out that rule was never actually a rule
The Top 20 Common Errors Checklist 3 min read Just a quiet feeling something's off, no lecture wanted — twenty fixes worth knowing, no fluff attached
Uneven Lists & Unfinished Comparisons 10 min read Your tidy list of likes trailing into a comparison that never finishes — here's the fix
Why Do I Accidentally Write Double Negatives? 11 min read "Double negative", scrawled in the margin again — why we write them, and the register where they're fine
Why Do I Get Marked for "Me and Him Went" or "Between You and I"? (Pronoun Case) 11 min read Marked down for "me and him went" or "between you and I" — the fix that finally sticks
Why Do I Keep Getting "A / An / The" Wrong? (Article Headaches) 10 min read That mark circling "the" or "a" on your essay — the three-question check that ends the guessing
Why Do My Descriptions Land on the Wrong Word? 9 min read A sentence felt perfectly sensible until someone underlined it — where descriptive words actually belong, and why it matters
Why Do My Tenses Keep Slipping? 13 min read That dragon story starts in the past and drifts into present tense halfway through — here's the fix
Why Does My "Correct" Grammar Sound Stiff, Wordy, or Just... Off? 11 min read Every rule followed, every comma right, yet the sentence still reads like a 1953 memo — here's why
Why Does My Preposition Feel Wrong? 10 min read The sentence reads fine yet something itches — the fixed preposition pairing your ear already half-knows
Why Does My Subject Not "Match" My Verb? (Subject–Verb Agreement) 9 min read Red pen scrawls S-V AGR with zero explanation — find the phrase that's hijacking your verb
Why Doesn't My Pronoun Match? (incl. Singular They) 10 min read Someone circled 'they' and wrote 'unclear' in the margin — the case for singular they, sorted
Why Doesn't My Reader Know What "It" or "This" Is Pointing To? (Vague Pronoun Reference) 9 min read Someone replies "sorry, which one?" to your Friday email — making "it" and "this" point somewhere clear
Word-Level Trouble — Which Problem? 2 min read The sentence shape is fine, the full stops sit right, yet one word keeps snagging — track it down