How to Form the Plural of Any English Noun: 6 Simple Rules (with Examples and Exceptions)
What are those mysterious plurals, and how do they work in English?
Let’s take a brief look before we get down to six specific spelling rules for making nouns plural. I’ll be giving you some common examples of nouns for each rule, as well as important exceptions to remember.
Your job is to find more nouns and add them to the list for each rule. Consider this an English plural reference guide that you can continue to use as your English advances.
- How Do Plurals Work in English?
- 6 Rules for Forming the Plural of Any English Noun
- 1. When to Add -s
- 2. When to Add -es
- 3. When to Add -ies
- 4. When to Add -i
- 5. When to Do Nothing
- 6. When to Remember Irregular Forms
How Do Plurals Work in English?
A singular noun in English refers to one person, thing, place or idea. A plural noun refers to more than one person, thing, place or idea.
What’s it like in your native language? Do you use the same word for both?
Some languages make no grammatical distinction between singular and plural. But in English, we do some fancy stuff to make our nouns plural.
The difference between the singular and plural forms of a noun are reflected in spelling. As you’ll see below, there are a number of spelling rules that can be applied to change a noun from singular to plural. The pronunciations of the plural and singular forms are usually slightly different as well.
Like many English rules, there are exceptions that apply only to certain plural nouns. What’s also interesting is that some nouns are always plural, some are always singular and some look the same in their singular and plural forms.
I know this may sound slightly overwhelming right now. But I’m going to simplify it for you and tell you exactly how these rules work. The list below would also be useful as a reference whenever you need to refresh your memory.
6 Rules for Forming the Plural of Any English Noun
1. When to Add -s
For most regular English nouns, you simply add the letter -s after the noun. Easy, right?
Here are a few common examples:
dog → dogs
car → cars
apple → apples
There are also specific word categories (…and some exceptions, unfortunately!) that you can learn in groups to make things even easier.
Nouns Ending in -th or -ph
If the noun ends in -th or -ph, simply add an -s after it, just like with the common words above.
mouth → mouths
photograph → photographs
Nouns Ending in -o
The general rule for nouns ending with the letter -o is to simply add -s after it.
Some common examples of such nouns are:
photo → photos
taco → tacos
piano → pianos
Exception: Add -es Instead
The exception to this rule is that for some nouns ending with the letter -o, you add -es after the noun instead. There aren’t any strict grammar rules here, so pay attention to these words when you encounter them and try to memorize them.
potato → potatoes
tomato → tomatoes
hero → heroes
cargo → cargoes
Nouns Ending in -f or -fe
The general rule is that for nouns ending in the letter -f or -fe, you simply add an -s at the end.
Here are some common examples:
roof → roofs
giraffe → giraffes
Exception: Use -ves Instead
The exception to this rule is that for some nouns ending in -f or -fe, instead of adding -s after the noun, you drop the -f or -fe and add -ves.
Here are a few common examples that are helpful to remember:
leaf → leaves
knife → knives
Nouns Ending in -on
For most nouns ending in -on, you simply add -s at the end.
lemon → lemons
canyon → canyons
salon → salons
Exception: Use -a Instead
For certain nouns ending in -on, drop -on and add -a at the end of the word.
You probably won’t encounter this exception very often, but it’s still important to know—especially if you’re using English for school or science, where you might need to use these words:
criterion → criteria
phenomenon → phenomena
2. When to Add -es
Some nouns always end in -es in the plural form.
Nouns Ending in -s, -x, -z, -sh or -ch
For nouns ending with the letters -s, -x, -z, -sh or -ch, simply add -es after the noun.
These examples show nouns with each of these endings:
bus → buses
box → boxes
buzz → buzzes
wish → wishes
watch → watches
Nouns Ending in -is
You still need -es to form the plural here, but you don’t just stick it onto the singular form.
For nouns ending in -is , drop the -is and then add -es.
Let’s look at some common examples:
axis → axes
oasis → oases
crisis → crises
3. When to Add -ies
There’s only one common type of word where you need to add -ies in the plural form. However, as you’ll see below, there’s also an important exception to this rule.
Nouns Ending in -y
For nouns ending with the letter -y, the general rule is to drop the -y and add -ies after the noun.
fairy → fairies
candy → candies
dummy → dummies
Exception: Just Add -s
Good news! There’s actually an easy way to remember when you need this exception. Just look for a vowel before the letter -y in the singular form.
If a vowel comes before the letter -y, then it’s easy. You simply add -s after the noun.
way → ways
monkey → monkeys
toy → toys
guy → guys
4. When to Add -i
Here’s another easy rule that you only need for one type of word.
Nouns Ending in -us
For nouns ending in -us, drop -us and add -i at the end of the word.
A few common examples are:
fungus → fungi
cactus → cacti
stimulus → stimuli
5. When to Do Nothing
As we mentioned earlier, there are a couple types of words where you don’t need to learn different singular and plural spellings.
Nouns with the Same Plural and Singular Forms
Talk about easy! There are some words that are exactly the same in their singular and plural forms.
Some common examples are below. You might notice that a lot of these words have to do with biology or animals.
Nouns with No Singular Forms
Then there are some nouns that have no singular forms. This means they’re always plural. So you don’t need to learn a singular form, because there isn’t one.
In general, most of these are things that work in pairs. But we should be careful not to assume that this guideline applies to everything that works in pairs.
You’ll see these most often in clothing vocabulary, such as:
pants (or: trousers)
Nouns with No Plural Forms
These nouns are also called mass nouns. They have no distinct plural forms. Typically, they refer to nouns that often come in groups, or nouns that are somewhat abstract. For example:
6. When to Remember Irregular Forms
If you’ve been an English learner for some time, you know there’ll always be special cases that don’t fit into any fixed formats or follow any rules. Here we have irregular nouns, which break all of the plural spelling rules we’ve discussed so far.
Yes, irregular nouns are like those children at the playground who walk up the slides instead of sliding down or who stand on the swings instead of sitting on them.
They do things differently from everyone else and that’s what makes them so interesting.
Okay, let’s look at some examples:
child → children (not “childs”)
mouse → mice (not “mouses”)
man → men (not “mans”)
woman → women (not “womans”)
die → dice (not “dies”)
With irregular nouns, there are basically no rules. As you can see, you cannot simply apply any of the rules and exceptions like we’ve done with the other regular nouns. So the only thing you can do is to close your eyes and memorize them and their plural forms.
So now, I hope you have a clearer picture of how to make nouns plural and spell them correctly.
Outside of this list, try to listen to how native speakers use these in their speech. If you don’t have natives around you, find a language exchange partner, or start watching English-language movies and TV shows.
Or you could try a virtual immersion program. FluentU, for example, takes authentic English videos and turns them into language lessons. Each video has annotated subtitles and a review quiz to test your knowledge of the material.
As you watch English language content (especially with subtitles), you’ll get more familiar with how plurals work in English by hearing them in context.
It may take some time to become familiar with the rules but that’s okay. To learn them quicker, print out a copy of these rules and keep them handy for your reference. Pretty soon, you’ll be an expert at plural spellings. Good luck!