Punctuation and Mechanics
What the domain tests
Punctuation questions test commas, semicolons, colons, dashes, apostrophes, quotation marks, hyphens, and capitalisation. The underlying concepts are separation (joining or dividing clauses and items) and possession (showing ownership or contraction). Mechanics also covers capitalising proper nouns and titles, and formatting numbers and abbreviations consistently.
Traps to watch
- Comma splices. A comma cannot join two independent clauses on its own.
- Semicolon misuse. A semicolon joins independent clauses or separates complex list items; it cannot introduce a list after a verb like includes.
- Colon rules. A colon follows a complete clause and introduces an explanation, list, or quotation.
- Apostrophe confusion. Its is possessive; it's means it is. Plural nouns take s'; singular nouns take 's.
- Restrictive versus non-restrictive clauses. Essential information takes no commas.
- Quotation placement. Periods and commas go inside closing quotation marks in standard usage.
Rule of thumb
Test whether the words on each side of a mark could stand alone as sentences. If yes, use a semicolon, a colon, or a comma with a conjunction, never a bare comma. For apostrophes, ask whether the word shows possession or a contraction.
Worked example
The team celebrated its victory; the coach praised its discipline. Both halves are independent, so the semicolon is correct and its is possessive.