Spelling, punctuation and grammar marks are some of the most winnable in the 11+ — in spot-the-mistake questions and in writing. The same errors come up again and again. Here are twenty to fix, each with a simple rule.
Apostrophes
1. Its vs it's
Rule: it's only ever means "it is" or "it has". Its shows possession.
✔ It's raining. ✔ The dog wagged its tail.
2. Plural possessives
Rule: if the plural ends in -s, add the apostrophe after it. If it doesn't, add 's.
✔ the girls' changing room (many girls) ✔ the children's books ✔ the men's team
3. Apostrophes in plurals
Rule: plurals never need an apostrophe.
✘ I bought three apple's. ✔ I bought three apples.
4. Names ending in s
Rule: both James's and James' are generally accepted. Pick one and be consistent — but an apostrophe is still needed.
Commas and sentence punctuation
5. The comma splice
Rule: a comma can't join two complete sentences on its own.
✘ It was late, we went home. ✔ It was late, so we went home. ✔ It was late; we went home.
6. Commas after fronted adverbials
Rule: put a comma after a phrase that starts the sentence and tells when, where or how.
✔ After lunch, we played football. ✔ Without warning, the lights went out.
7. Commas in lists
Rule: commas separate items; in British school English there's usually no comma before the final "and".
✔ We packed sandwiches, crisps, apples and juice.
8. Commas around extra information
Rule: if you could remove the phrase and the sentence still works, it needs a comma on both sides.
✔ My brother, who is fourteen, plays the drums.
9. Semicolons vs colons
Rule: a semicolon joins two closely related sentences. A colon introduces a list, an explanation or an example.
✔ The sun was setting; the birds fell silent. ✔ She had one goal: to win.
Direct speech
10. Punctuation inside the inverted commas
✘ "Come here" she said. ✔ "Come here," she said.
11. New speaker, new line
Rule: start a new paragraph every time the speaker changes.
12. Capital letters in speech
Rule: speech starts with a capital letter, but when a sentence of speech is split, the second part doesn't.
✔ "I think," said Tom, "that we're lost."
Homophones and confusables
13. There / their / they're
✔ There is a place. ✔ Their shows belonging. ✔ They're = they are.
14. Your / you're
✔ Is this your coat? ✔ You're (you are) late.
15. Practice / practise, advice / advise
Rule: in British English, the c spelling is the noun and the s spelling is the verb. Remember: ice is a noun.
✔ I need to practise for football practice.
16. Affect / effect
Rule: usually, affect is the verb (action) and effect is the noun (end result).
✔ The rain affected the match. ✔ The rain had an effect on the match.
Grammar
17. Subject-verb agreement
Rule: the verb must match the subject — even when words come in between.
✘ The box of chocolates were empty. ✔ The box of chocolates was empty.
18. Mixing tenses
Rule: stay in one tense unless the time really changes. Stories are usually in the past tense.
✘ She opened the door and sees a fox. ✔ She opened the door and saw a fox.
19. "Should of" and "could of"
✘ I should of known. ✔ I should have known. (It sounds like "should've".)
20. Me / I
Rule: remove the other person to check.
✘ Me and Sam went. (Me went?) ✔ Sam and I went. ✔ Mum took Sam and me.
How to practise SPAG for the 11+
- One rule at a time. Spend a week on apostrophes before moving to commas. Unsure of a term? See our grammar glossary.
- Learn the tricky spellings. Start with our 11+ spelling list.
- Practise in the exam format. GL-style papers split a sentence into lettered sections and ask which contains the mistake.
- Read work aloud. Missing words and comma splices are easier to hear than to see.
- Keep a personal list of the mistakes your child makes most often, and check for those first.
Elevenplus FC covers spelling, homophones, punctuation, apostrophes, commas, direct speech, semicolons and colons, grammar, tenses, subject-verb agreement, pronouns, connectives, active and passive voice, and sentence structure — including GL-style spot-the-mistake questions and a Grammar Decoder. See 11+ SPAG practice.
Frequently asked questions
What is the most common SPAG mistake in the 11+?
Apostrophes — especially its/it's and plural possessives — are among the most common, along with comma splices and homophones such as there/their/they're.
How can my child get better at spotting SPAG mistakes?
Learn the rules one at a time, practise spot-the-mistake questions in the exam format, and read work aloud slowly — many errors are easier to hear than to see.