top of page

Lesson 1.2a Irregular plural nouns

downloadable worksheet


There used to be lots more ways to make plurals in English. In Old English (spoken from about 500-1000), some plurals were also formed by adding -s, which is still, of course, the way that most nouns form their plurals now.


One of the other main ways to form plurals in Old English was by changing the vowel. The plural of book was bec, for example. Now we say books, of course, but we still have other plurals formed by changing the vowel of the singular, such as goose to geese or tooth to teeth. Can you come up with other words that form their plurals by changing their vowels?


In Old English the plural of eye was eyen. Are there words we still pluralize by adding -en?


And finally, Old English had a large group of nouns that had the singular and plural form, such as deer (which used to mean ‘animal,’ not ‘deer’).


What are some other words we still pluralize by adding nothing at all?


Then, in the 17th and 18th centuries, English began to borrow a great many words from Latin and Greek. Most of these words had to do with advances in science, technology, medicine, and the arts. Sometimes these words retained the Latin or Greek plurals. Words that ended in -on like phenomenon have -a for the plural: phenomena (also criterion/criteria), and nouns ending in -is take -es: hypothesis/hypotheses, parenthesis/parentheses. Because we speak English, not Latin or Greek, we tend to want to just add -s to form plurals on these words as well, or to treat the plural like the singular. If we’re speaking Greekified English, though, we should say a phenomenon but these phenomena.


Make the following words plural and use them in a sentence. Some of them may not be familiar as singulars.








You may need to look up some in a dictionary to see how the meanings of the singular and plural forms may have come to have different meanings (medium, for example).



key words: nouns, parts of speech, irregular nouns, subject-verb agreement


CCSS.ELA-Literacy.L.3.1a: Explain the function of nouns, pronouns, verbs, adjectives, and adverbs in general and their functions in particular sentences. 

CCSS.ELA-Literacy.L.3. 1b: Form and use regular and irregular plural nouns.

CCSS.ELA-Literacy.L.3.1f: Ensure subject-verb and pronoun-antecedent agreement. 


Here is this lesson as a pdf.

bottom of page