Singular and Plural Nouns
a) Most nouns for their plural by adding -s to the singular noun.
book ⇢ books day ⇢ days girl ⇢ girls
b) We add -es is to the singular noun ends in -ch, -sh, -s or -x.
church ⇢ churches dish ⇢ dishes bus ⇢ bushes box ⇢ boxes
c) Some nouns ending in -o (tomato, potato, echo, hero, negro are the most common) add -es in the plural. Other nouns ending in -o add -s only.
tomato ⇢ tomatoes potato ⇢ potatoes piano ⇢ pianos radio ⇢ radios
d) Nouns ending in a consonant + – y, change -y to -i and add -es.
baby ⇢ babies factory ⇢ factories lorry ⇢ lorries
2. Irregular Plurals
a) Some nouns ending in -f / -fe drop the -f / -fe and add -ves in the plural.
half ⇢ halves thief ⇢ thieves leaf ⇢ leaves knife ⇢ knives wife ⇢ wives life ⇢ lives
b) Some nouns form the plural by changing their vowel(s).
*The plural of mouse is mice.
foot ⇢ feet tooth ⇢ teeth goose ⇢ geese man ⇢ men woman ⇢ women mouse ⇢ mice.
c) A few nouns form the plural with -en.
child ⇢ children ox ⇢ oxen
d) Some nouns have the same form in the singular and plural.
sheep ⇢ sheep deer ⇢ deer fish ⇢ fish aircraft ⇢ aircraft series ⇢ series species ⇢ species
e) Some nouns borrowed from Greek and latin have Greek or Latin plural endings.
crisis ⇢ crises phenomenon ⇢ phenomena
f) The usual plural of person is people. (not persons)
*Fish is the normal plural of fish; fishes is also possible, but less usual.
person ⇢ people