Third Grade English: Sentence Mechanics & Structure - Apostrophes in Contractions and Possessives
Apostrophes are specialized punctuation marks that perform two distinct, indispensable jobs in written English: assembling contractions by substituting for missing omitted letters, and signaling noun possession to indicate ownership and relationship. Because the apostrophe looks identical in both situations, many young writers confuse contractions with possessive nouns, or accidentally insert unnecessary apostrophes into simple plural words. In this chapter, you will master the mechanics of forming common contractions, explore the differences between homophone pairs like its/it's and their/they're, and discover reliable tests to keep your apostrophes in the exact right spot.
The Dual Nature of the Apostrophe
An apostrophe never sits on the baseline like a comma or period; it floats high in the air between letters. It performs two jobs only:
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| THE TWO JOBS OF THE APOSTROPHE |
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| |
| JOB 1: CONTRACTIONS (Omission of Letters) |
| Replaces missing letters when two words shrink into one. |
| do + not -----> don't (Apostrophe replaces the 'o') |
| |
| JOB 2: POSSESSIVES (Ownership & Relationship) |
| Shows that a noun owns or possesses something. |
| the dog + bone -> the dog's bone (The bone of the dog) |
| |
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Job 1: Contractions (Shrinking Words)
A contraction is a single shortened word created by combining two smaller words and replacing one or more letters with an apostrophe.
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| ORIGINAL WORDS | CONTRACTION | LETTERS REPLACED |
+---------------------+-------------------+---------------------+
| is not | isn't | o |
| cannot | can't | n, o |
| will not | won't | Irregular shift |
| did not | didn't | o |
| I am | I'm | a |
| you are | you're | a |
| we have | we've | h, a |
| they will | they'll | w, i |
| she would | she'd | w, o, u, l |
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The Placement Rule for Contractions
The apostrophe must sit in the EXACT space where the missing letters were removed—not wherever you feel like putting it!
- WRONG: did'nt (The 'o' was between n and t, so putting the apostrophe between d and n is wrong!).
- CORRECT: didn't (The apostrophe sits precisely where the 'o' was removed).
- WRONG: does'nt
- CORRECT: doesn't
The Unusual Contraction: "Won't"
"Will not" does not become "willn't." In historic English, the phrase shrank into "won't." It is the most famous irregular contraction in the English language!
Job 2: Possessives (Showing Ownership)
As you learned in our grammar study, apostrophes show ownership on nouns.
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| POSSESSIVE NOUN APOSTROPHE RULES |
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| SINGULAR NOUN : Add 's |
| - The girl's bicycle (One girl owns the bicycle). |
| |
| PLURAL NOUN ENDING IN S : Add ' only |
| - The girls' soccer team (Many girls share the team). |
| |
| IRREGULAR PLURAL NOUN : Add 's |
| - The children's playground (Many children share the park).|
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The Showdown: Contractions vs. Possessive Pronouns
This is the ultimate battleground of third grade mechanics. Possessive pronouns NEVER use apostrophes, while contractions ALWAYS use apostrophes!
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| CONTRACTION | POSSESSIVE PRONOUN | DIAGNOSTIC TEST |
| (HAS Apostrophe!) | (NO Apostrophe!) | |
+-----------------------+-----------------------+---------------------+
| it's = it is | its = belonging to it | Substitute "it is" |
| they're = they are | their = belonging | Substitute "they are|
| you're = you are | your = belonging to u | Substitute "you are"|
| who's = who is | whose = belonging | Substitute "who is" |
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The "Expansion Test"
Whenever you are unsure whether to write "it's" or "its," expand the word into "it is":
- Sentence: "The puppy wagged (its / it's) tail."
- Test with "it is": "The puppy wagged it is tail." -> Sounds ridiculous!
- Result: Use the possessive pronoun WITHOUT an apostrophe: "The puppy wagged its tail."
- Sentence: "(Its / It's) raining outside."
- Test with "it is": "It is raining outside." -> Makes complete sense!
- Result: Use the contraction WITH the apostrophe: "It's raining outside."
The "Never-Plural" Rule
The number one apostrophe error in the English language is putting an apostrophe into a simple plural word.
- WRONG: "I love eating apple's and orange's."
- CORRECT: "I love eating apples and oranges."
- Remember: An apostrophe is NOT a warning that an 's' is approaching! An apostrophe shows missing letters (contractions) or belonging (possessives). If there are just multiple items, write a plain 's' with NO apostrophe!
Practice Exercises and Review
Put your apostrophe mastery to the test.
Exercise 1: Form the Contractions
Write the contraction for each pair of words.
1. could not
2. we are
3. they have
4. will not
Exercise 2: Its vs. It's
Choose the correct word for each sentence.
1. _ (Its / It's) time to pack our bags for the field trip.
2. The bluebird fed _ (its / it's) hungry chicks in the nest.
3. I love this jacket because _ (its / it's) lining is fleece.
Exercise 3: Correct the Apostrophe Errors
Find and fix the apostrophe mistakes in this sentence: "The two cat's climbed onto the sofa because they did'nt want to get wet."
Answer Key and Explanations
- Exercise 1:
- couldn't
- we're
- they've
- won't
- Exercise 2:
- It's (Expands to: "It is time to pack...").
- its (Possessive pronoun showing ownership of chicks).
- its (Possessive pronoun describing lining).
- Exercise 3:
- "cat's" should be simple plural "cats" (no ownership).
- "did'nt" should be "didn't" (apostrophe goes between n and t where 'o' was dropped). Corrected: "The two cats climbed onto the sofa because they didn't want to get wet."