5.6 Form, Structure & Sense: Genitives and Plurals
Key Takeaways
- College Board's testing point covers choices among singular, plural, singular possessive, and plural possessive forms, plus possessive determiners, contractions, and adverbs.
- The three-way its / it's, their / they're / there, and your / you're sets are named explicitly in the official framework and are among the most frequently tested items in the domain.
- Plural nouns never take an apostrophe: 1990s, sensors, and scientists are plurals, not possessives.
- Singular possessive adds apostrophe-s (the scientist's data); plural possessive of a noun already ending in -s adds only an apostrophe (the scientists' data).
- The reliable test is substitution: expand the contraction (it is / they are / you are) and see whether the sentence still works.
The Testing Point in Full
This is the most specific description in the entire Assessment Framework, and it repays close reading:
Students will make contextually appropriate choices among singular, plural, singular possessive, and plural possessive nouns and pronouns and among possessive determiners (its, their, your), contractions (it's, they're, you're), and adverbs (there).
College Board is naming the exact word sets it tests. That is unusual, and it means you can prepare for these items almost exhaustively.
The Four-Way Noun Choice
Most items in this testing point offer the same noun in four forms and ask which the sentence needs.
| Form | Meaning | Example |
|---|---|---|
| scientist | one person | "The scientist presented the findings." |
| scientists | more than one — no apostrophe | "Three scientists presented the findings." |
| scientist's | belonging to one | "The scientist's findings were disputed." |
| scientists' | belonging to more than one | "The three scientists' findings were disputed." |
The decision procedure is two questions:
- Is anything owned? If nothing in the sentence belongs to the noun, you need a plain singular or plural — no apostrophe at all. This eliminates two choices immediately.
- If something is owned, is the owner one or many? One owner → -'s. Multiple owners already ending in -s → apostrophe only.
A test for step 1: try inserting of the — "the findings of the scientists." If that paraphrase works, you need a possessive. If it does not, you need a plain plural.
Plurals Never Take Apostrophes
This is the single most violated rule in written English, and the exam tests it directly.
- ✓ "The 1990s saw three major revisions." — not 1990's
- ✓ "The lab installed six sensors." — not sensor's
- ✓ "Both committees met in April." — not committee's
An apostrophe signals possession (or a contraction). It never signals "more than one."
Irregular Plurals
Nouns whose plural does not end in -s form the plural possessive with -'s, exactly like a singular:
| Singular | Plural | Plural possessive |
|---|---|---|
| child | children | children's |
| woman | women | women's |
| person | people | people's |
| mouse | mice | mice's |
"The children's section reopened" — never childrens'. The apostrophe follows the complete plural form, and children is already complete.
The Three Named Sets
its / it's
| Word | What it is | Test |
|---|---|---|
| its | possessive determiner | "The committee published its report." |
| it's | contraction of it is or it has | "It's raining." → "It is raining." ✓ |
Expand it. If it is or it has fits, use it's. Otherwise use its. There is no third form: its' is not a word.
their / they're / there
| Word | What it is | Example |
|---|---|---|
| their | possessive determiner | "The researchers submitted their data." |
| they're | contraction of they are | "They're submitting the data today." |
| there | adverb of place, or an existential subject-filler | "The data are over there." / "There are four samples." |
Note that College Board explicitly lists there as an adverb in this set — it is testing the three-way confusion, not just the two-way possessive/contraction one.
your / you're
| Word | What it is | Example |
|---|---|---|
| your | possessive determiner | "Bring your calculator." |
| you're | contraction of you are | "You're allowed one break." |
Possessive Pronouns Take No Apostrophe
None of the possessive pronouns uses an apostrophe: its, hers, his, ours, yours, theirs, whose.
- ✓ "The decision was theirs." — not their's
- ✓ "The scholar whose work we cited…" — not who's, which means who is
Whose versus who's follows the identical logic as its versus it's: expand the contraction and see whether it fits.
Singular Nouns That Already End in -s
A singular noun that already ends in -s still takes -'s, because the rule keys off number, not spelling:
- ✓ "The class's schedule changed twice." — one class
- ✓ "The bus's route was extended." — one bus
- ✓ "The witness's testimony was recorded." — one witness
Contrast "the classes' schedules" — there the plural classes already ends in -s, so it takes the bare apostrophe. Official items keep these unambiguous: College Board does not build questions on the contested house-style cases (Dickens' versus Dickens's), because a scored question needs exactly one defensible answer.
Joint Versus Separate Possession
When two owners are named, the position of the apostrophe says whether they own one thing together or one thing each:
| Form | Meaning |
|---|---|
| "Watson and Crick's 1953 paper" | a single paper, written jointly |
| "Watson's and Crick's notebooks" | separate notebooks, one apiece |
Joint ownership marks only the last name in the pair; separate ownership marks both. The surrounding sentence supplies the answer — a singular object after the blank usually points to joint possession, a plural object to separate possession.
Reading the Blank's Neighbors
Because every item in this testing point offers four forms of the same word, the fastest opening move is to look at what sits immediately after the blank:
| What follows the blank | What the blank needs |
|---|---|
| A noun — "______ findings" | Probably a possessive; then decide singular or plural |
| A verb — "______ were digitized" | A plain subject noun, no apostrophe |
| The end of the clause | A plain noun; nothing is being owned |
This does not replace the of the test, but it narrows four choices to two in a couple of seconds — and conventions items are exactly the ones you want to finish quickly to bank time for the longer Craft and Structure passages.
Worked Examples
Example 1. "The committee published ______ findings in June, and ______ expected to reshape the field." First blank: possession by the singular committee → its. Second blank: expands to it is expected → it's.
Example 2. "Both ______ notebooks were digitized, though neither scientist attended the ceremony." Two owners, and notebooks of the scientists works → plural possessive → scientists'.
Example 3. "The archive holds more than four thousand ______ from the 1930s." Nothing is owned; the noun is simply plural → recordings, not recording's.
Section Takeaways
- Ask whether anything is owned before anything else; if not, no apostrophe belongs.
- Plural nouns never take apostrophes, including decades such as 1990s.
- Singular possessive adds -'s; plural possessive of an -s plural adds only an apostrophe; irregular plurals add -'s.
- Expand it's / they're / you're / who's into it is / they are / you are / who is to test them.
- Possessive pronouns — its, hers, ours, theirs, whose — never take an apostrophe.
- A singular noun already ending in -s still takes -'s (the class's schedule); joint owners mark only the last name.
A passage reads: "The committee published ______ findings in a June report, and ______ expected to reshape how the field measures soil carbon." Which choice completes the text so that it conforms to the conventions of Standard English?
A passage reads: "The archive holds more than four thousand field ______ made during the ______ in rural Georgia." Which choice completes the text so that it conforms to the conventions of Standard English?
Which sentence is punctuated correctly?
Which of the following sentences contain an apostrophe error? (Select all that apply)
Select all that apply