Many English learners make the same mistake by adding ‘s’ to words that should never have it! In this guide, you’ll discover 16 common words that students incorrectly try to make plural. From uncountable nouns like ‘equipment’ to irregular plurals like ‘mice’, you’ll learn why adding an ‘s’ is incorrect and see clear examples to help you use each word correctly. Master these tricky words to avoid common mistakes and sound much more natural in English!

6. Gymnastics/maths

Now, how about these nouns: “gymnastics” and “maths”? They both end in -s 

• But are they singular, plural or uncountable?
• Can we add -es to make them plural?

No, we can’t add -es. “Gymnastics” and “maths” are uncountable nouns that happen to end in -s.

Here are a few more nouns that look plural, but are actually uncountable and singular:

• Physics Physics is my favourite subject at school.
• Politics Politics plays a big role in everyday life.
• Economics She studied economics before pursuing medicine.
• News The news was very upsetting
• Measles Measles is a serious illness, especially for children.

7. The general public: a singular noun which refers to ordinary people

The general public (correct) the general publics (incorrect)

“The general public” can be followed by a singular or a plural verb.

• The general public is divided on the issue.
• The general public are divided on the issue.

8. Police

• I reported the crime to the polices. (incorrect)
• I reported the crime to the police. (correct)

“Police” is a plural noun and it always takes a plural verb.

• The police are investigating.

Many nouns that end in -s are always plural, like scissors, trousers and clothes. We don’t say a scissor or a trouser, or scissorses or trouserses.

8. tooth

• I have two wobbly tooths. (incorrect)
• I have two wobbly teeth. (correct)

9. mouse

• One mouse => two mice (not two mouses)

Here are a few more irregular plurals

• Child => children
• Person => people
• Goose => geese
• Woman => women
• Man => men
• Crisis => crises

10. sheep

• There are more than 50 sheeps in that field. (incorrect)
• There are more than 50 sheep in that field. (correct)

Sheep = singular and plural form

• There was one lonely sheep in the barn. (correct) => singular
• When I can’t sleep, I count sheep. (correct) => plural

Here are a few more nouns that have the same singular and plural forms:

Note: “fishes” is also correct but only when you’re talking about different species of fish. So if you saw many kinds, you could say:

We saw lots of colourful fishes. (many kinds)