3.3 Apostrophes: Possession and Contractions
Key Takeaways
- Add 's to most singular nouns to show possession; for plural nouns ending in s, add only an apostrophe after the s.
- Joint possession takes an apostrophe on the final noun only; individual possession requires an apostrophe on each owner.
- Its is possessive; it's means it is or it has—never use it's for simple possession.
- Your/you're, whose/who's, and similar pairs mix possession with contractions and are frequent TEAS traps.
- Do not use apostrophes to form ordinary plurals of nouns; use care with decades and plurals of letters.
Two Jobs Only (Almost)
The apostrophe (') has two primary jobs in standard English tested on the TEAS:
- Show possession (ownership or close association).
- Mark contractions (omitted letters in combined words).
A third, narrower use appears in certain plurals of letters or unusual forms—but never use an apostrophe to make a regular noun plural (patients, not patient's, when you simply mean more than one patient).
Healthcare documentation is full of ownership language: the patient's allergy list, the nurses' station, the hospital's policy. Mixing those patterns is a classic exam distractor set.
Singular and Plural Possession
| Situation | Pattern | Example |
|---|---|---|
| Singular noun | add 's | the patient's chart; the nurse's badge |
| Singular noun ending in s (common academic choice) | usually 's | Dr. Williams's note; the boss's office |
| Plural noun ending in s | add only ' after the s | the patients' lounge; the nurses' schedules |
| Irregular plural not ending in s | add 's | children's doses; women's clinic; men's room |
| Shared (joint) ownership | apostrophe on the final noun only | Maria and Jamal's shared care plan |
| Individual ownership | apostrophe on each noun | Maria's and Jamal's separate assignments |
Singular vs. plural possessives — hear the difference:
- Patient's vital signs = one patient owns the vitals.
- Patients' vital signs = vitals belonging to multiple patients (for example, a unit report).
Writers reverse these constantly. On TEAS, count the owners first, then place the apostrophe.
Joint vs. Individual Possession
- Joint: The charge nurse and educator's workshop implies one workshop belonging to both (apostrophe on the last name/noun only when structured as joint).
- Individual: The charge nurse's and the educator's workshops implies each person has a workshop.
If the owned noun is singular (one plan, one room), joint possession is likely. If the owned noun is plural and the owners do not share the same items, use individual apostrophes.
Healthcare charting example: "Update both parents' contact numbers" (two parents, shared category of numbers listed for each) differs from "Update the parent's contact number" (one parent). Context decides; grammar marks the decision.
Contractions Forms
Contractions replace omitted letters with an apostrophe:
| Contraction | Full form |
|---|---|
| it's | it is / it has |
| you're | you are |
| who's | who is / who has |
| they're | they are |
| we're | we are |
| isn't / aren't / wasn't | is not / are not / was not |
| let's | let us |
| I've / we've / they've | I have / we have / they have |
Academic and clinical writing often prefers full forms (it is, they are) in formal notes, but TEAS will still test whether you recognize the correct contracted spelling and meaning.
High-Yield Confusable Pairs
These pairs mix possessive pronouns (no apostrophe) with contractions (apostrophe). Possessive pronouns already show ownership, so they never take apostrophes.
| Form | Role | Memory cue | Correct example |
|---|---|---|---|
| its | possessive pronoun | like his / hers (no apostrophe) | The clinic updated its policy. |
| it's | contraction | = it is / it has | It's time for rounds. / It's been an hour. |
| your | possessive determiner | ownership | Check your login. |
| you're | contraction | = you are | You're assigned to Room 12. |
| whose | possessive | ownership | Whose stethoscope is this? |
| who's | contraction | = who is / who has | Who's covering lunch? |
| their | possessive | ownership | Their vitals are stable. |
| they're | contraction | = they are | They're waiting for transport. |
| there | place / placeholder | location or there is | The cart is over there. |
Substitution test: Expand the contraction. If it is, you are, or who is fits, keep the apostrophe form. If expansion sounds wrong, use the possessive without an apostrophe.
- "The monitor lost it's signal" → expand to "it is" → nonsense → use its.
- "Its time for medication" → need "It is" → use It's.
Never Apostrophes for Simple Plurals
| Wrong | Right | Why |
|---|---|---|
| The nurse's are busy. | The nurses are busy. | Plural subject, not possession |
| Check two ID's. | Check two IDs. | Modern style often drops apostrophe in all-caps plurals |
| Order lab's. | Order labs. | Simple plural noun |
| Keep the scissor's sterile. | Keep the scissors sterile. | Plural tool name |
Using an apostrophe to "make a plural" is one of the most common errors TEAS-style questions expect you to catch in revision stems.
Decades, Letters, and Special Cases
Style guides differ slightly, but TEAS-friendly academic habits include:
| Case | Preferred pattern | Example |
|---|---|---|
| Decades as plurals | usually no apostrophe | the 1990s; the 2020s |
| Plural of a single letter | apostrophe often used for clarity | Mind your p's and q's; three A's on the rubric |
| Plural of abbreviations | often no apostrophe | RNs, CNAs, CBCs |
| Possessive of abbreviation | apostrophe applies | the RN's assessment; the RNs' meeting (one vs. many) |
Do not write the 1990's when you merely mean the decade as a plural span of years; the apostrophe incorrectly suggests possession or an old-fashioned plural. If you mean possession—the 1990s' fashion trends—the plural decade becomes a possessive with the apostrophe after the s.
Names, Brands, and Clinical Nouns
- Singular proper names: Dr. Ramirez's order, St. Mary's Hospital (the hospital name may already include a possessive form as a proper noun—copy official names exactly).
- Plural family names: the Smiths (family), the Smiths' home (possession by the family).
- Inanimate ownership is still possession grammatically: the hospital's policy, the medication's half-life, the wound's edges. English allows this; you do not need a human owner.
Healthcare charting example: "Document the wound's length, width, and depth in centimeters" uses a singular possessive. "Document all wounds' measurements on the flow sheet" uses a plural possessive because multiple wounds own measurements.
TEAS Trap Checklist for Apostrophes
- Plural or possessive? If you only mean more than one, no apostrophe.
- One owner or many? patient's vs. patients'.
- Contraction or possessive pronoun? Expand it's / you're / who's.
- Joint or separate ownership? Apostrophe on last only vs. on each.
- Decade or letter plural? Avoid decorative apostrophes in 2020s; allow clarity apostrophes in A's if needed.
Work the checklist slowly in practice; on test day it becomes a five-second scan that prevents the most common wrong answers.
Which sentence uses its/it's correctly?
Which choice correctly shows plural possession for multiple nurses?
Choose the sentence that correctly distinguishes whose and who's.
Which sentence avoids an incorrect apostrophe for a simple plural?