¶ The Library

Common Errors

The young-learner edition — same rules, smaller steps, friendlier examples.

19 articles For readers 8–18 See the adult edition

Young LearnersUK & US

In this pillar

Every young-learner article

Start here The Mistakes Everyone Makes 3 min read The red-pen moments everyone gets — named, explained and fixed in five minutes

Affect/Effect, Accept/Except, Principle/Principal 4 min read Circle after circle round "affect", or maybe "effect" — the three pairs that trip everyone up
Commas, Semicolons & Colons — Fast Triage 4 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 4 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 4 min read A pink circle round "it's" changed to "its" — the four mix-ups everyone makes, sorted for good
Some/Any/Much/Many/Fewer/Less 4 min read Red pen round "less" when you meant "fewer" — the busy pairs finally sorted for good
The Grammar Myths Clinic (Split Infinitives &c.) 4 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 2 min read A red mark, a green squiggle, or just a feeling a sentence is off — scan the 20 most common slips and grab the fix.
Uneven Lists & Unfinished Comparisons 4 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? 4 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) 4 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) 4 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? 4 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? 4 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? 4 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? 4 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) 4 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) 4 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) 4 min read Someone replies "sorry, which one?" to your Friday email — making "it" and "this" point somewhere clear