Apostrophes Beyond the Basics
Apostrophes: Joint Possession, Irregular Plurals, and Time
Knowing where to put the apostrophe can be tricky when you move past simple singular nouns. For example, do you write Mark and Sarah's apartment (because they share it) or Mark's and Sarah's cars (because they each have one)? What about irregular plurals like women's clothing, or time expressions like three months' delay?
This challenge tests your ability to navigate these trickier punctuation rules. You will help a landlord address his tenants, complete a detective's report on a cheese heist, and finalize a royal guest list. The questions cover joint vs. separate possession, irregular plural possessives, compound nouns, and time expressions.
You'll work through 10 questions in a mix of single-choice, multi-choice, drop-down, and drag-and-drop formats.
Try the quiz to check your knowledge!
Apostrophe
Its vs it's: the single most confused pair in English punctuation. It's = it is (contraction). Its = belonging to it (possessive, no apostrophe — like his or hers).
The apostrophe ( ' ) has exactly two jobs: marking possession (the teacher's desk) and marking contractions (don't, we're). It does not create plurals — two cats, never two cat's.
Diagnostic: try expanding to it is. If the sentence works → write it's. If not → write its. For nouns, ask: does it mean "belongs to"? Yes → add 's. No → just add s for the plural.
Noun
Noun vs verb: the two core word classes. Nouns name things; verbs describe actions/states. Many English words can be both (run, play, cook, work) — only the sentence slot tells you which role it's playing. The run was exhausting (noun) vs I run every day (verb).
A noun names an entity. It interacts with articles, determiners, forms plurals, and controls verb agreement and pronoun choice.
Diagnostic: can you put the/a before it or pluralise it? → noun. Does it describe an action with tense? → verb. Can it do both? → check the sentence context.
Possessive
Noun possessive vs pronoun possessive: nouns ADD an apostrophe for possession (Sarah's, students'). Pronouns NEVER use apostrophes (its, yours, theirs — no apostrophe). This contradiction is why its/it's is the most common error in English writing.
The possessive marks ownership: 's for singular nouns, s' for plural nouns ending in s, and special pronoun forms (my/mine, their/theirs).
Diagnostic: is it a noun? → add 's or s'. Is it a pronoun? → use the built-in possessive form (NO apostrophe). Specifically its (possessive) vs it's (it is).
Pronoun
Pronoun vs noun: nouns name explicitly (Sarah, the book). Pronouns substitute and point back (she, it). Pronouns are a closed class (you can't invent new ones easily), while nouns are open (new ones appear constantly). The main complication: pronouns still carry case marking that nouns have lost.
A pronoun replaces a noun or noun phrase. Types: personal, demonstrative, relative, interrogative, reflexive, indefinite.
Diagnostic: every pronoun must have a clear antecedent (the noun it replaces). If the reader can't tell which noun a pronoun refers to → ambiguity error.
Punctuation
Punctuation vs grammar: grammar governs word forms and order. Punctuation governs how you mark the structure on paper. You can have perfect grammar with wrong punctuation (comma splices in otherwise correct sentences), and you can have correct punctuation with broken grammar. They're parallel systems.
Punctuation = the system of marks that make written sentence structure visible: periods, commas, semicolons, colons, apostrophes, dashes, and quotation marks.
Diagnostic: if your grammar is correct but readers misparse your sentences → punctuation problem. If punctuation is fine but word forms/order are wrong → grammar problem.
B1 | Intermediate
B1 vs B2: B1 handles standard everyday communication and simple opinions. B2 handles abstract topics, sustained arguments, and nuanced register. If you can chat about your life but struggle to debate an issue or write a formal essay, you're B1.
B1 is the intermediate CEFR level: independent handling of familiar topics, second conditional, basic passive, reported speech, and linking words for cause and contrast.
Diagnostic: can you read a newspaper article on a familiar topic and summarise the argument? Comfortably → B2. Struggle with abstractions → still B1.
Medium
Medium vs Easy: Easy has one obviously correct answer and clearly wrong distractors. Medium has one correct answer but plausible distractors — you need to actually know the rule, not just guess from sound.
The Medium tag filters for A2–B1 challenges with realistic difficulty: one rule per question, plausible alternatives, everyday contexts.
Diagnostic: if you're scoring 90%+ on Easy, move here. If you're below 60% on Medium, go back to Easy for that topic. Target 70–80% accuracy for maximum learning.