¶ The Library

Common Errors

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

19 articles For readers 11–18 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 Three pairs that swap places in everyone's writing — a quick test for each so you never mix them up again
Commas, Semicolons & Colons — Fast Triage 4 min read Not sure which mark to use? A quick decision guide for commas, semicolons and colons when you're mid-sentence
Fragments, Run-Ons & Comma Splices 4 min read The three ways a sentence goes wrong at its edges — too short, too long, or wrongly joined; each with a fix
Its/It's, Their/There, Your/You're, Then/Than 4 min read The apostrophe lookalikes that cost easy marks — one quick test each for its/it's, their/there and the rest
Some/Any/Much/Many/Fewer/Less 4 min read The quantity words that follow hidden rules — some or any, much or many, fewer or less, sorted with clear tests
The Grammar Myths Clinic (Split Infinitives &c.) 4 min read "Never split an infinitive", "never start with and" — the fake rules you can safely ignore, and why they stuck
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 "I like reading, films and to swim" — how a list trips when its parts don't match, and how to even it out
Why Do I Accidentally Write Double Negatives? 4 min read "I didn't do nothing" says the opposite of what you mean — how two negatives cancel out, and how to fix it
Why Do I Get Marked for "Me and Him Went" or "Between You and I"? (Pronoun Case) 4 min read "Me and him went" gets circled — the drop-the-other-person trick that tells you when it's I or me, he or him
Why Do I Keep Getting "A / An / The" Wrong? (Article Headaches) 4 min read A, an or the — the tiny words that trip up so much writing; here's how to know which one a sentence needs
Why Do My Descriptions Land on the Wrong Word? 4 min read "Running for the bus, my bag fell" — how a describing phrase drifts onto the wrong thing, and how to anchor it
Why Do My Tenses Keep Slipping? 4 min read Starting in the past and sliding into the present mid-story — how to catch a tense that wanders and hold it steady
Why Does My "Correct" Grammar Sound Stiff, Wordy, or Just... Off? 4 min read Every rule followed, and it still sounds robotic — why over-correct writing feels stiff, and how to loosen it
Why Does My Preposition Feel Wrong? 4 min read "Different to" or "different from"? The little linking words that never quite feel right, sorted
Why Does My Subject Not "Match" My Verb? (Subject–Verb Agreement) 4 min read "The list of names are long" — why the verb grabs the wrong word, and how to match it to the real subject
Why Doesn't My Pronoun Match? (incl. Singular They) 4 min read When "everyone" meets "their" — how to make a pronoun agree with what it stands for, singular they included
Why Doesn't My Reader Know What "It" or "This" Is Pointing To? (Vague Pronoun Reference) 4 min read "This is a problem" — but which this? How a floating it or this loses your reader, and how to pin it down