Grammar: Word classes: Nouns: Noun formation

Singular and plural forms

Plural nouns with irregular patterns

If the noun ends in '-o', then the plural is often formed by adding '-es':

singular	plural
echo go hero mosquito tomato	echoes goes heroes mosquitoes tomatoes

However, there are some exceptions:

singular	plural
kilo photo piano radio video	kilos photos pianos radios videos

A useful rule of thumb here is that these words are often abbreviated: kilogram, photograph, pianoforte, radiogram, video-cassette recorder.

For some nouns which end in '-f'  or  '-fe',   the plural is formed with '-ves':

singular	plural
half knife leaf life wife	halves knives leaves lives wives

However, there are some exceptions:

singular	plural
belief chief roof	beliefs chiefs roofs

Some common nouns have a very irregular form in the plural:

singular	plural
child foot man mouse sheep woman	children feet men mice sheep women

Other nouns with irregular plural forms include criterion/criteria, phenomenon/phenomena. However, words such as these tend to be foreign words, and are not likely to be encountered at primary level.

How can I help my students to use words like scissors?

There is a small group of nouns which refer to tools and articles of clothing which behave in a special way in English. Although they refer to a single object, words like scissors are plural, and are often used with a pair of. It helps to think of them as consisting of two parts. Here are some examples:

You can see a long way through these binoculars.
My glasses were very expensive.
I'm going to buy a pair of jeans.
Can I borrow your headphones?
Aren't these pyjamas cute.
I need a new pair of sunglasses.
Those trousers are too dirty.