How to Form Possessive Nouns Ending in “S”

Forming a normal possessive in English is relatively simple – to indicate possession, you add an apostrophe and an “s” to the end of a regular or proper noun. But what about when the noun you want to make possessive already ends in “s?” Should you add another “s,” or just the apostrophe?

In general, if the noun ends in “s” because it is plural, you simply add an apostrophe after the “s”. If you want to form a possessive from a noun ending in “s,” you can do so in two ways, depending on the style you’re following. You can simply follow normal possessive rules or add only an apostrophe.

There is a trick you can use to make possessive forms easier. Read on to learn what it is.

Plural Nouns

The easiest possessive formation explanation is that of regular plural nouns. This rule is a true rule – it always applies, no matter what the regular plural noun is.

If you’re showing a plural noun as possessive, you add only an apostrophe, every time. Here are some examples.

The cars’ owners were excited to swap notes.
The dogs’ tails wagged happily.
The houses’ prices were rising.

In each of these sentences, it’s clear that there are multiple subjects included in the noun – multiple cars, dogs, and houses.

Irregular Plural Nouns

Some irregular plural nouns don’t end in “s,” so they follow the same rules as regular singular nouns.

Men’s shoes are expensive.
He is the people’s choice.

The rest of the irregular plural nouns still end in “s,” though, so they follow the same rules as regular plural nouns.

The axes’ values were different.
The students were looking for the analyses’ meaning.
The appendices’ contents were worth looking at.

Most, if not all, plural nouns follow very straightforward rules of possession. The singular nouns ending in “s” are where the debates start to crop up.

The Singular Apostrophe versus Apostrophe “S” Debate

The most basic way to form a possessive is to add an apostrophe and an “s” to the end of a noun. However, there are plenty of singular nouns which end in “s.” Bus, lens, mess, news – the list goes on. So, does the same rule apply? It all depends on who you ask.

Some sources, such as the AP Style Guide, argue that any word ending in “s” is made possessive simply by adding an apostrophe. This causes problems, however, because of how plural nouns are made possessive.

Take, for instance, the word “series.” “Series” is spelled the same way whether it’s used as a singular or plural noun. So:

The series’ writing was good.

Could mean that there is a singular series possessing the writing, or multiple series possessed the writing. If it’s written as:

The series’s writing was good.

Then, though it sounds strange, it’s clear that you’re talking about a singular series. The answer, then, when it comes to regular singular nouns, depends on the style guide you’re following, but the consensus seems to be that, unless you’re specifically told otherwise, you would continue to add an apostrophe and an “s.”

The One-Syllable Rule

Something most (but of course, not all) experts can agree on is the one-syllable rule. This rule is very basic – if a singular noun ending in “s” has more than one syllable, it is to be made possessive with only an apostrophe. This is usually applied to names and places, so, for example:

To show Mr. Jones possessing something, you would write “Mr. Jones’s.”
To show Mr. Matthis as possessing something, you would write “Mr. Matthis’.”

One strange exception to this rule is the country of Wales, whose official website declares that the only correct possessive form of the name is “Wales’.”


If you want a straight answer, then you’re going to be disappointed – the rules for possessive forms in English are complicated at best and nonexistent at worst. The most you can work with is convention and feedback.

For the sake of simplicity, you can follow some simple guidelines:

  • Plural nouns only get an apostrophe(after the s).
  • Singular nouns that don’t end in “s” get an apostrophe before the “s.”
  • Singular nouns that do end in “s” should follow the one-syllable rule.

Unless you’re specifically corrected, these are the rules to use. They’re the least likely to read strangely in your writing and the least confusing to remember. Possessive forms are strange, but they’re not impossible to learn.