The Comprehensive Diagnostic Quiz
Here's the thing — this isn't a test, and nobody's keeping score. It's a quick sweep across the whole library, twenty-five short probes touching sentence structure, verbs, agreement, punctuation, capitals and word choice. Answer each one the way you would in a real email or a bit of homework, then let the key send you straight to the article that fixes whatever wobbled. That's the whole job of this page: it finds, it doesn't teach.
The quiz
Pick the best answer. Don't agonise — a gut answer tells you more than a laboured one.
1. Which is a complete sentence? A) Because the train was late. B) The train was late. C) When the train arrived at last.
2. Neither of the answers ___ right. A) is B) are
3. Which uses the past perfect correctly? A) By the time I arrived, they left. B) By the time I arrived, they had left.
4. The dog wagged ___ tail. A) it's B) its
5. Which mark correctly joins these two complete thoughts? I finished the report ___ I still need to check the figures. A) , (comma only) B) ; C) no mark at all
6. Where do the capitals belong? on monday we visit the british museum. A) On monday we visit the British Museum. B) On Monday we visit the British Museum. C) On Monday we visit the british museum.
7. The stronger choice in formal writing: The teacher gave the book to ___. A) who B) whom
8. The weather will ___ our plans. A) affect B) effect
9. Which is not a run-on or a comma splice? A) She opened the window, the room cooled quickly. B) She opened the window the room cooled quickly. C) She opened the window, and the room cooled quickly.
10. Which apostrophe is right when several students own the books? A) the students books B) the student's books C) the students' books
11. Which modal shows strong necessity? You ___ submit the form by Friday. A) can B) might C) must
12. Which sentence is in the passive voice? A) The committee approved the plan. B) The plan was approved by the committee.
13. Everyone brought ___ own lunch. A) their B) his C) its
14. Which uses the colon correctly? A) I need three things: milk, bread and eggs. B) I need: milk, bread and eggs.
15. Which uses the semicolon well? A) We packed quickly; gloves, scarf and boots. B) The rain stopped; the sun came out.
16. Choose the right forms. ___ car broke down, so ___ taking the bus. A) Their / they're B) They're / their C) There / their
17. Which shows correct title case (headline style) for this book? a short history of nearly everything A) A Short History Of Nearly Everything B) A short history of nearly everything C) A Short History of Nearly Everything
18. Which places the opening phrase so it points at the right thing? A) Running for the bus, my bag fell open. B) Running for the bus, I dropped my bag.
19. Which is a correct second conditional? A) If I won the lottery, I will buy a house. B) If I won the lottery, I would buy a house.
20. Which article fits? She is ___ honest person. A) a B) an
21. In direct speech with a dialogue tag, which is standard? A) "Come in", she said. B) "Come in," she said.
22. Which is correct in formal standard English? A) I could of finished earlier. B) I could have finished earlier.
23. For someone you know who uses they, which is right? A) They left their bag here. B) They left his bag here. C) He or she left their bag here.
24. Which is spelled correctly? A) seperate B) separate
25. Which list is correctly punctuated? A) We bought apples, bread and cheese. B) We bought apples, bread, and cheese. C) Both are acceptable.
Answer Key
Use this only after you've had a go. Each "if you missed this" line sends you home to the article that owns the fix — there's no new teaching here, just directions.
| Q | Answer | If you missed this → |
|---|---|---|
| 1 | B | Pillar 3 (Sentence Structure) — fragments |
| 2 | A | Pillar 5 (Agreement) — subject–verb agreement |
| 3 | B | Pillar 4 (The Verb System) — past perfect / tense sequencing |
| 4 | B | Pillar 2 (Parts of Speech) — its vs it's |
| 5 | B | Pillar 6 (Punctuation) — semicolons; and Pillar 3 — comma splices |
| 6 | B | Pillar 7 (Capitalisation) — days and proper names |
| 7 | B | Pillar 2 (Parts of Speech) — pronouns (who / whom) |
| 8 | A | Pillar 8 (Spelling & Word Choice) — confusables (affect / effect) |
| 9 | C | Pillar 3 (Sentence Structure) — run-ons and comma splices |
| 10 | C | Pillar 6 (Punctuation) — possessive apostrophes; and Pillar 2 — possessives |
| 11 | C | Pillar 4 (The Verb System) — modals |
| 12 | B | Pillar 4 (The Verb System) — passive voice |
| 13 | A | Pillar 5 (Agreement) — pronoun–antecedent agreement (singular they) |
| 14 | A | Pillar 6 (Punctuation) — colons |
| 15 | B | Pillar 6 (Punctuation) — semicolons |
| 16 | A | Pillar 8 (Spelling & Word Choice) — confusables (their / there / they're) |
| 17 | C | Pillar 7 (Capitalisation) — titles |
| 18 | B | Pillar 3 (Sentence Structure) — modifiers |
| 19 | B | Pillar 4 (The Verb System) — conditionals |
| 20 | B | Pillar 2 (Parts of Speech) — articles (a / an by sound) |
| 21 | B | Pillar 6 (Punctuation) — quotation marks |
| 22 | B | Pillar 8 (Spelling & Word Choice) — could have vs could of |
| 23 | A | Pillar 5 (Agreement) — pronoun–antecedent agreement (singular they) |
| 24 | B | Pillar 8 (Spelling & Word Choice) — spelling |
| 25 | C | Pillar 6 (Punctuation) — commas in lists (the serial comma is a house-style choice) |
A word on UK and US
Nothing here is a dialect trap. Where the two standards genuinely part ways, both answers count.
- Question 25 turns on the serial (Oxford) comma before and — optional in UK and US alike, so both readings are fine.
- Collective nouns would split the same way: the team are playing (a common UK reading, picturing the members) sits happily beside the team is playing (the usual US reading). Neither is marked wrong.
- Spelling systems — colour [US: color], organise [US: organize] — and terms like full stop [US: period] never decide an answer above.
If a question needed a single tick, it's on a point both standards agree on.
What to do with your results
Don't fret over the total. Look at the pattern.
Any pillar that comes up more than once in your misses is where your time is best spent — start there. If your misses are scattered, begin with Pillar 3 (Sentence Structure) and Pillar 6 (Punctuation); they quietly steady most of the others. And if you just want a fast refresher rather than a full read, the quick charts in Pillar 12 (pieces 4–8 and 10) cover tense, agreement, punctuation, capitals and confusables at a glance.
Good news — if the key sent you somewhere specific, that is the homework. One pillar at a time beats a dozen vague evenings of "I really should sort my grammar out." You've got a map now. Use it.
Where the routes lead
- Pillar 2 — Parts of Speech (pronouns, articles, its / it's, possessives)
- Pillar 3 — Sentence Structure & Syntax (clauses, fragments, run-ons, modifiers)
- Pillar 4 — The Verb System (tenses, modals, passive, conditionals)
- Pillar 5 — Agreement & Concord (subject–verb, pronoun–antecedent, singular they)
- Pillar 6 — Punctuation (commas, semicolons, colons, apostrophes, quotation marks, hyphens)
- Pillar 7 — Capitalisation
- Pillar 8 — Spelling, Morphology & Word Choice (confusables, spelling systems)