Comma vs Apostrophe Quiz: Test Yourself
Five quick questions on comma vs apostrophe. Pick an answer to get instant feedback.
Flip Cards: Quick Review
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A mark on the line that separates items or clauses.
“We bought eggs, milk, and bread.”
A raised mark for possession or missing letters.
“The dog’s leash.”
A shortened word; the apostrophe marks the missing letters.
“It’s late.” (it is)
A form that shows ownership, often with ’s.
“The teacher’s desk.”
People mix up comma vs apostrophe because the two marks look nearly identical at a glance. The apostrophe is basically a comma lifted off the line. What matters is where the mark sits and what it does, and that is easy to learn once you know the rules.
| Term | Meaning | Part of speech / Category | Example sentence |
|---|---|---|---|
| Comma (,) | Separates items, clauses or extra information | Punctuation / sits on the line | “We packed tents, stoves, and maps.” |
| Apostrophe (possession) | Shows that something belongs to someone | Punctuation / sits high | “The professor’s argument was clear.” |
| Apostrophe (contraction) | Replaces missing letters in a shortened word | Punctuation / sits high | “They don’t care.” (do not) |
| Simple plural | More than one; takes no apostrophe | Grammar / no mark | “We saw three dogs.” |
What does a comma do?
A comma separates parts of a sentence so that it is easy to read. It sits on the line of text, with a small tail that dips slightly below it.
Common uses include:
- Lists: “She bought apples, pears, and plums.”
- After an introduction: “After dinner, we took a walk.”
- Joining clauses: “It was late, but we kept driving.”
- Large numbers: “The city has 1,000,000 residents.”
Comma rules have a lot of detail, and even writing guides admit they are less clear-cut than apostrophe rules.
What does an apostrophe do?
An apostrophe has two main jobs: it shows possession and it marks missing letters in contractions. It sits at the top of the line, which is why it looks like a comma floating in the air.
- Possession: “the dog’s leash,” “the organization’s needs.”
- Contractions: “it’s” (it is), “don’t” (do not), “we’ll” (we will).
The iron rule is that an apostrophe does not make a simple plural. If a word is neither a contraction nor a possessive, it gets no apostrophe.
Comma vs apostrophe: how can you tell them apart?
Look at position and purpose. A comma sits on the baseline and separates things. An apostrophe sits at the top of the letters and either shows ownership or replaces missing letters.
A quick test: if you can expand the word into two words, as in “it’s” to “it is,” you need an apostrophe. If you are separating items or clauses, you need a comma.
How do you use an apostrophe to show possession?
For most singular nouns, add ’s: the dog’s leash. For plural nouns that already end in s, add only the apostrophe after the s: the dogs’ leashes.
Singular nouns that end in s trip up many writers, so check your style guide. The main point is to ask first whether the word is singular or plural, then place the mark.
Do plurals need an apostrophe?
No. Simple plurals never take an apostrophe. Write “three dogs,” not “three dog’s,” and “the 1990s,” not “the 1990’s.”
The mistake is so common that it has a nickname, the greengrocer’s apostrophe. It happens because people see a final s and reach for the mark.
What is the difference between its and it’s?
It’s is a contraction of “it is” or “it has.” Its, with no apostrophe, is the possessive form, as in “the cat licked its paw.”
The same pattern holds for your/you’re, their/they’re and whose/who’s. Possessive pronouns never take an apostrophe, while the contractions always do.
Can mixing up the comma and apostrophe change meaning?
Yes. Punctuation can change who is doing what. “Let’s eat, Grandma” invites someone to dinner, while “Let’s eat Grandma” is a very different sentence.
Apostrophe mistakes cause similar problems: “the teams victory” and “the team’s victory” are not the same, and one of them reads as an error.
How can you remember comma vs apostrophe?
Think of height and job. The comma crouches on the line to separate, and the apostrophe floats up high to show belonging or missing letters. The tricks below give you quick checks.
Common mistakes with commas and apostrophes
- ✗ The cat licked it’s paw.
✓ The cat licked its paw. - ✗ We bought apple’s and pear’s.
✓ We bought apples and pears. - ✗ The dogs bowl was empty.
✓ The dog’s bowl was empty. - ✗ We bought eggs milk and bread.
✓ We bought eggs, milk, and bread. - ✗ Your welcome.
✓ You’re welcome.
Memory tricks
- Comma crouches, apostrophe floats. One sits on the line, and the other sits high.
- Expand it. If “it’s” can become “it is,” the apostrophe is right. If not, drop it.
- Apostrophes show belonging or something missing. If neither is true, no apostrophe.
FAQ: Comma vs Apostrophe
What is the difference between a comma and an apostrophe?
A comma sits on the line and separates items, clauses or extra information. An apostrophe sits high and shows possession or marks missing letters in a contraction.
Is an apostrophe the same as a comma?
No. They look similar, but an apostrophe is raised to the top of the text and has different jobs. Using one in place of the other will confuse readers.
Do plurals need an apostrophe?
No. Simple plurals never take an apostrophe. Write dogs and the 1990s, not dog’s or the 1990’s.
Is it its or it’s?
It’s is a contraction of it is or it has. Its with no apostrophe is the possessive form, as in the cat licked its paw.
Where does the apostrophe go in a plural possessive?
For plural nouns that end in s, add the apostrophe after the s, as in the dogs’ bowls. For plurals that do not end in s, add ’s, as in the children’s toys.
Conclusion
The comma vs apostrophe difference comes down to position and purpose: a comma separates on the line, and an apostrophe shows possession or missing letters up high. Check each mark against the expand-it test and you will avoid the most common errors. Share this with someone who mixes these up.