8 Rules for Plural Nouns in English, Including Tricky Irregular Words

If you think the only way to make plural nouns in English is by adding -s to a word, this blog post is for you. Even though there are several nouns that only require the addition of the letter -s, there are many others that follow different rules. We will go over all 8 rules regarding making plural nouns and give you many examples of sentences using the plurals. Keep reading for more and test your knowledge at the end of this blog post by doing our exercises. 

All the rules for making plurals

In the following sections, we will show you the eight rules for making plurals in English. Some rules are easy to apply, but some of them you will need to memorize. Let’s get started! 

1. Simply add the letter s to a noun

For most nouns, the rule is simple: add the letter s to the end of the word, and that forms the plural version. This happens with common words like book, sofa, chair, computer, phone, car, and many others. Here are some examples:

• I need to buy 4 books for college. 
• I’ve only driven 2 cars in my whole life. 
• There are 10 chairs in the classroom. 

2. For some nouns, add es to make them plural

If a word ends in the letters s, x, z, ch, and sh, you add es to the end to make it plural. This rule is true for words like bus, box, witch, quiz, and brush, for example. In the plural form, they are buses, boxes, witches, quizzes, and brushes. Here are some of those nouns being used in examples:

• I had 5 quizzes in my Spanish class last week. 
• I need only 2 brushes to do my makeup. 
• Both buses are late. I will take the subway to college. 

3. Drop the y, add ies for nouns like city or lady

Now, if a noun ends in y, we need to drop the y and add ies to form the plural. Some words that this rule applies to are: baby, city, library, lady, and berry. In the plural form, they are babies, cities, libraries, ladies, and berries. Here are some examples:

• I love babies. How do you feel about them? 
• My favorite American cities are Los Angeles and Miami. 
• Ladies and gentlemen, please take a seat. The show is about to begin! 

However, there are some exceptions to this rule for making plurals. If the singular noun ends in y but the letter before the y is a vowel (like ay or ey), you just need to add an s to make the plural form. This happens with words such as boy, play, ray, turkey, monkey, and tray. 

4. Drop the f and fe, add ves  for nouns like life or self

This is another rule for making plurals in English. For nouns that end in f and fe, we need to drop them and add ves. Some examples are wife, calf, elf, loaf, and self. Take a look at the sentences below: 

• He has a good relationship with his ex-wives. 
• I bought two loaves of bread yesterday. 
• We need to take better care of ourselves. 

However, there are some exceptions to this rule. Here are four words that do not follow the ves rule: 

• roof / roofs 
• belief / beliefs
• chef / chefs
• chief / chiefs

5. Does it end in o? You may need to add es (but not always!) 

When we have a singular noun that ends in o, we simply add es to make it plural. This is true for words like potato, tomato, mosquito, domino, and hero. Take a look at the examples below: 

• She always makes potatoes for lunch. 
• I hate mosquitoes! 

However, for those words which have a vowel before the o (like oo or io) we just need to add s. The words zoo and studio are some examples of this rule.  

• I love going to zoos. 
• The major movie studios are located in Hollywood. 

If the letter before the -o is a consonant, but the word is a shortened version of some other word, such as photo (short for photograph), we simply add -s. That’s why we say I like taking photos instead of I like taking photoes. 

Questions about these tricky words? You can read more about making plurals for nouns ending in -o here. 

6. For words ending in us, the plural ends in i 

Here is another word for making plural nouns in English. If a word ends in us, the plural version of the noun will end in i. This is true for words like cactus, focus, and campus, for instance. Take a look at the examples below: 

• There are many different varieties of cacti. 
• Several famous alumni have agreed to help raise money for the school’s restoration fund. 

7. These nouns don’t change at all 

These nouns are different because they don’t change at all. Just remember them when you talk about multiples and don’t add anything to the end of the word. The only way you can identify if they are singular or plural is by looking them in context. Here are some of the words with irregular plural nouns in English: 

• sheep
  How many sheep are there? (multiple sheep)
  I saw a sheep in the field. (single sheep)
• deer
  The deer like to eat tree bark. (multiple deer)
  There is a deer in the yard! (single deer)
• fish 
  We have eight fish in this tank. (multiple fish)
  This fish is dead. (single fish)
• moose
  Those moose are huge animals. (multiple fish)
  Look at that baby moose! (single fish)
• shrimp 
  This dumpling has a shrimp in it. (multiple shrimp)
  The shrimp are eaten by whales. (single shrimp)

8. Irregular nouns, because sometimes English doesn’t follow the rules

Some nouns follow no specific rules when it comes to pluralization. That’s why they also need to be memorized. Here are the most common single and plural irregular nouns in English: 

• child / children 
• man / men 
• woman / women 
• goose/ geese 
• person / people 
• tooth / teeth 
• foot / feet 
• mouse / mice 

Exercises about plural nouns in English 

So you think you know the 8 rules for plural nouns? Test your knowledge with this exercise!

Being able to pluralize nouns is important for any English learner, so we do hope this blog post is helpful to you! Also, make sure to read this blog post about possessions in English to learn how to use an apostrophe (‘). If you have any questions about this topic, share your comment down below. Happy studying!