The choice between sisters or sister’s depends on what you mean. Use sisters when you mean more than one sister. Use sister’s when something belongs to one sister, or when you mean “sister is” or “sister has” in a contraction.
These two forms look almost the same, but the apostrophe changes the grammar. That small mark can change a sentence from a simple plural to possession.
Correct: My sisters live in Denver.
Correct: My sister’s car is in the driveway.
The first sentence talks about more than one sister. The second sentence talks about one sister and her car.
Quick Answer
Use sisters for the plural noun: “I have two sisters.” Use sister’s for one sister’s possession: “My sister’s phone is ringing.” Sister’s can also be short for “sister is” or “sister has,” as in “My sister’s coming over.”
Why People Confuse Them
People confuse sisters and sister’s because both forms sound very similar in normal speech. In writing, the only visible difference is the apostrophe.
The confusion also happens because English uses apostrophes for more than one job. An apostrophe can show possession, as in my sister’s room. It can also show missing letters, as in my sister’s here, meaning “my sister is here.”
The biggest mistake is adding an apostrophe just because a word ends in s. A plain plural noun does not need an apostrophe.
Wrong: I have two sister’s.
Correct: I have two sisters.
Key Differences At A Glance
| Context | Best Choice | Why |
|---|---|---|
| More than one female sibling | sisters | It is the plural form. |
| Belonging to one sister | sister’s | It shows singular possession. |
| “Sister is” | sister’s | It works as a contraction. |
| “Sister has” | sister’s | It can also shorten “has.” |
| Belonging to more than one sister | sisters’ | This is the plural possessive form. |
A simple way to remember it: sisters means more than one. Sister’s points to one sister plus ownership or a shortened verb.
Meaning and Usage Difference
Sisters is a plural noun. It means two or more sisters.
Example: My sisters are both teachers.
Sister’s is usually a singular possessive form. It means something belongs to, relates to, or is connected with one sister.
Example: My sister’s apartment is near campus.
Sister’s can also be a contraction. In that case, it means sister is or sister has.
Example: My sister’s working late tonight.
Meaning: My sister is working late tonight.
Example: My sister’s finished her homework.
Meaning: My sister has finished her homework.
Pronunciation does not usually help much because these forms often sound alike. The sentence meaning tells you which spelling fits.
Tone, Context, and Formality
There is no strong tone difference between sisters and sister’s. Both are normal in everyday, school, business, and personal writing.
The difference is grammar, not formality.
Use sisters when counting or naming more than one sister.
Example: Her sisters helped plan the party.
Use sister’s when the sentence points to one sister and something connected to her.
Example: Her sister’s speech made everyone laugh.
In formal writing, be careful with contractions. My sister’s applying today is fine in casual writing, but My sister is applying today may look cleaner in a school paper, resume note, or professional email.
Which One Should You Use?
Choose sisters when the sentence can answer “How many?” If the answer is two or more, you probably need the plural form.
Example: I invited my sisters to dinner.
Choose sister’s when the sentence can be turned into an “of my sister” idea.
Example: My sister’s laptop is new.
Meaning: The laptop of my sister is new.
Also choose sister’s when it clearly means “sister is” or “sister has.”
Example: My sister’s been busy all week.
Meaning: My sister has been busy all week.
Compact comparison:
- sisters = more than one sister
- sister’s = belonging to one sister
- sister’s = sister is / sister has
- sisters’ = belonging to more than one sister
When One Choice Sounds Wrong
Sisters sounds wrong when you need possession for one sister.
Wrong: My sisters phone is broken.
Correct: My sister’s phone is broken.
Sister’s sounds wrong when you only mean more than one sister.
Wrong: My sister’s are coming over.
Correct: My sisters are coming over.
It also sounds wrong if the sentence needs a plural subject. Since sister’s points to one sister or a contraction, it should not replace a plain plural noun.
Wrong: Her sister’s live in Chicago.
Correct: Her sisters live in Chicago.
One more form matters here: sisters’. Use it when something belongs to more than one sister.
Correct: My sisters’ room is upstairs.
Meaning: The room belongs to both sisters.
Common Mistakes (and Quick Fixes)
Mistake 1: Using an apostrophe for a plural.
Wrong: I miss my sister’s.
Correct: I miss my sisters.
Mistake 2: Leaving out the apostrophe for possession.
Wrong: My sister car needs gas.
Correct: My sister’s car needs gas.
Mistake 3: Using sister’s for more than one sister’s possession.
Wrong: My sister’s birthdays are in May and June.
Better: My sisters’ birthdays are in May and June.
Mistake 4: Forgetting that sister’s can be a contraction.
Correct: My sister’s at work.
Meaning: My sister is at work.
Quick test: If you can replace sister’s with sister is or sister has, it is a contraction. If not, it probably shows possession.
Everyday Examples
My sisters are watching a movie in the living room.
My sister’s jacket is hanging by the door.
Both of my sisters play soccer.
My sister’s going to call you later.
My older sister’s advice helped me choose a college.
Her sisters live in different states.
My sister’s dog barks every morning.
The sisters opened a small bakery together.
My sister’s already left for the airport.
Their sisters joined us for lunch.
Notice how sisters names multiple people, while sister’s either shows a link to one sister or shortens “sister is” or “sister has.”
Dictionary-Style Word Details
Verb
sisters: Not commonly used as a verb in standard everyday US English. In this comparison, sisters works as a plural noun.
sister’s: Not a verb. It may include a shortened verb when used as a contraction, as in my sister’s leaving, meaning my sister is leaving.
Noun
sisters: A plural noun meaning more than one sister.
Example: My sisters text me every weekend.
sister’s: A possessive form based on the singular noun sister. It is used before another noun to show that something belongs to or relates to one sister.
Example: My sister’s schedule is full today.
Synonyms
sisters: Closest plain alternatives include female siblings or, more broadly, siblings. These are not always exact because siblings can include brothers.
sister’s: No true synonym fits because this is a grammar form, not a separate vocabulary word. Depending on the sentence, the closest explanation is belonging to one sister, sister is, or sister has.
Clear antonyms do not really apply to these forms. The comparison is about number and possession, not opposite meanings.
Example Sentences
sisters: My sisters helped me move into my apartment.
sisters: Do your sisters live nearby?
sister’s: My sister’s phone died during the trip.
sister’s: My sister’s making dinner tonight.
sister’s: My sister’s visited that museum before.
Word History
sisters: This form comes from sister plus s, the regular way many English nouns become plural.
sister’s: This form comes from sister plus an apostrophe and s. In modern writing, that ending can show possession or mark missing letters in a contraction.
The important history for this comparison is practical: English uses s for many plurals, but it uses an apostrophe to mark possession or omitted letters.
Phrases Containing
sisters:
- two sisters
- twin sisters
- older sisters
- sisters and brothers
- the sisters in the family
sister’s:
- my sister’s house
- her sister’s wedding
- your sister’s name
- my sister’s here
- his sister’s been busy
FAQs
Is sisters or sister’s correct?
Both are correct, but they mean different things. Use sisters when you mean more than one sister. Use sister’s when something belongs to one sister or when it means sister is or sister has.
What does sisters mean?
Sisters is the plural form of sister. It means two or more sisters.
Example:
My sisters are coming over tonight.
What does sister’s mean?
Sister’s usually shows possession for one sister.
Example:
My sister’s car is parked outside.
It can also mean sister is or sister has.
Example:
My sister’s working late tonight.
Is “my sister’s are here” correct?
No. The correct sentence is:
My sisters are here.
Use sisters because you are talking about more than one sister.
Is “my sisters phone” correct?
No. The correct sentence is:
My sister’s phone is ringing.
Use sister’s because the phone belongs to one sister.
What is the plural possessive of sisters?
The plural possessive is sisters’.
Example:
My sisters’ room is upstairs.
This means the room belongs to more than one sister.
Can sister’s mean “sister is”?
Yes. Sister’s can be a contraction for sister is.
Example:
My sister’s at school.
This means:
My sister is at school.
Can sister’s mean “sister has”?
Yes. Sister’s can also mean sister has.
Example:
My sister’s finished her homework.
This means:
My sister has finished her homework.
Should I use an apostrophe to make sisters plural?
No. Do not use an apostrophe to make sister plural. The correct plural is sisters, not sister’s.
Correct: I have three sisters.
Wrong: I have three sister’s.
What is the easiest way to remember sisters vs sister’s?
Use sisters for more than one sister. Use sister’s when one sister owns something or when the phrase means sister is or sister has.
Conclusion
The difference between sisters and sister’s is simple once you check the sentence.
Use sisters when you mean more than one sister. Use sister’s when something belongs to one sister or when the phrase means sister is or sister has.
