Feet, knives and sheep: Forming plurals in English 1

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by Liz Walter

For the majority of words in English, forming the plural is easy. All you need to do is add ‘s’. If the word ends in s, x, z, ch, or sh, you add ‘es’, otherwise it will be impossible to say. So, for example, we get tablesbirds, and teachers, or boxes, churches, and dishes.

However, as with most rules in English, there are lots of exceptions. I’ll start with some really common words that have irregular plurals. If you only have time to learn a few, learn these:

child > children

man > men

woman > women (remember the pronunciation is / ˈwɪm.ɪn /. I know it sounds unlikely, but trust me, it’s true!)

foot > feet

tooth > teeth

An interesting one is person > people. Persons is sometimes used in very formal contexts, such as legal documents, but people is by far the most common plural, and the one you need to use in 99% of cases.

There are a few other general rules that are worth learning. Firstly, if a word ends in a consonant sound + y, we drop the y and add ies. If it ends in a vowel sound + y, we just add s in the usual way. So we have baby > babies, family families, city > cities, and company > companies but donkeys, chimneys, runways, and birthdays.

Secondly, words ending in f or fe usually drop the f and add ves, for example knifeknives, leaf > leaves, life > lives, wifewives, shelf > shelves. One exception to this is roofs. The plural rooves used to be used, but roofs is the accepted form now –  nobody seems to know why this word changed while most other f or fe words didn’t!

Words that end in o usually simply add s, e.g. avocados, bistros, discos. However, a few end with oes and you just have to learn which ones they are. Four of the most common are echoes, heroes, tomatoes, and potatoes. And just to complicate things even further, a few words ending in can form their plurals either way, e.g., mosquitos/mosquitoes, mangos/mangoes, volcanos/volcanoes. If you’re not sure, check in a dictionary.

Oddly, a few words don’t change at all from singular to plural. So we can have one or lots of species, sheep, aircraft, deer or series.

Finally, a word of warning. Never, never, NEVER be tempted to use an apostrophe in a plural! It is wrongly used all over the place, especially in shops and cafés. ‘Potato’s’, ‘apple’s’, ‘ice cream’s’ – all of these are wrong and you will lose marks for writing them in an English exam.

That’s a look at the basic rules of plurals. But what about the more complicated ones? Is it terminus or termini? And why is the plural of ‘formula’ formulae? For more complex plurals see my next post.

20 thoughts on “Feet, knives and sheep: Forming plurals in English 1


    Great info on spelling, but nothing on pronunciation. (I know that theoretically the *spelling* of the word should tell you the *sounds* of the word, but English has clearly seen a divergence of the two things.)

    I.e. The sound of even regular plural endings differs depending on if the singular noun’s final sound is voiced, voiceless, sibilant etc. And then the ones that change from voiceless to voiced (like most “-f” nouns changing to “-ves”, or “houses”).


    1. Jere Lull

      An almost-serious question this reminded me of: If the plural of mouse is mice, Why isn’t the plural of spouse spice?

  2. Razvan

    Dear Liz,
    I would like to thank you for the articles, they are really helpful. I’ve been reading them for a while now but this is my first reply as I have my first question. I apologize if it is too off-topic. I was reading “Bartleby, The Scrivener A Story of Wall-Street” and I came across this odd use of the word “stationery”. As much as I have searched through different dictionaries I couldn’t find more than one meaning which doesn’t help me understand what Mr. Turkey meant by his reply.
    Here is a bit of context for it.
    Thank you so much!

  3. Senthilkumar

    Thank you ! it is very useful to write anything to anywhere.without article we are not able to write anything to anywhere .once again thank you to given the usage of article in English writing and reading skill thanks

  4. Debora

    Thans for this interesting and useful post. I would like to have some information about the words like quiz (plural: quizzes). What other words behave like this?

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