You’ll find that “sisters,” “sisters’,” and “sister’s” are spelt the same with minor differences (the apostrophe, namely).
We’ll help you understand why these words work in different contexts and how you can remember the best way to use them.
Sisters or Sisters’ or Sister’s?
“Sisters” is only the plural form. It does not come with any possession but refers to many “sisters.” You can use “sisters'” when those sisters own an object (i.e. “the sisters’ night out”). “Sister’s” works when one sister owns an object (i.e. “my sister’s dream”).
Here’s a quick, helpful tip for each form that we’ll go through:
| Singular | Sister |
| Plural | Sisters |
| Singular possessive | Sister’s |
| Plural possessive | Sisters’ |
“Sister” and “sister’s” are the singular forms. “Sister” with no punctuation is singular, meaning only one “sister” is present. With the ‘s ending, “sister’s” is the singular possessive form. This means one sister owns an item (i.e. “my sister’s keeper”).
The plural forms are “sisters” and “sisters’.” “Sisters” has no possession as no apostrophe is used. “Sisters'” with the apostrophe means that many sisters own an object that comes directly after the noun (i.e. “the sisters’ gathering”).
Sister’s
“Sister’s” is the singular possessive form. Here, only one sister owns an object, and you’ll find the object can come before or after the noun (depending on what makes more grammatical sense).
Nine times out of ten, the object comes after “sister’s.” This makes the possession clear to the reader. They don’t have to try and figure out why the apostrophe is used in this form:
- That’s my sister’s house. Since I had that run-in with her boyfriend, I haven’t been allowed back there.
- You need to consider your sister’s goals before moving forward. She comes first. She’s family.
In rare circumstances, you might find the object comes first. Here’s how that might look:
- That house is my sister’s.
Sisters’
“Sisters'” is the plural possessive form, meaning many sisters own an object or group of similar objects. It’s more common for a group of objects to come after the plural possessive form to clarify that many things are going on at once (i.e. “many of my sisters’ bedrooms”).
The plural possessive form implies that multiple people own multiple things. You will only find the owned “things” after the plural possessive form. It’s not likely that the objects will come earlier than the possessive form when used in this manner.
- The sisters’ bedrooms were all in a state. They needed to get them sorted before their parents returned.
- His sisters’ things were scattered all over the floor. Both of them would be fuming if they arrived home.
Sisters
While “sisters” is not a possessive form, it is still grammatically correct. You should use it to refer to many sisters in your writing. It is the plural form, which is an extension of the singular “sister.”
Adding an “s” to the end of a singular form is a common grammar rule in English. Most regular nouns use this when turning singular forms into plural forms, meaning that multiple instances of the same noun are present.
- How many sisters did you say she had? I can’t believe the size of her family!
- You have a lot of sisters. They’re going to help you get through a lot in your life.
Conclusion
“Sisters,” “sister’s,” and “sisters'” are spelt the same but have different uses.
“Sisters” refers to many sisters as it’s the plural form. There is no possession here.
“Sister’s” refers to a single sister, but she is allowed to own an object. “My sister’s keeper” works as a singular possessive phrase.
“Sisters'” refers to many sisters owning an object or group of objects. “The sister’s houses” is correct in the plural possessive form.