countable nouns- spelling

Here are some general rules for spelling plural nouns.

Nouns	Plural	Examples
Most nouns	add s	book, books; cup, cups; sprout, sprouts
Most nouns that end in ch, sh, s, x, or z	add es	box, boxes; bus, buses; prize, prizes
Most nouns that end in a vowel and y	add s	boy, boys; day, days; key, keys
Most nouns that end in a consonant and y	y becomes ies	baby, babies; country, countries; spy, spies
Most nouns that end in f or fe	f or fe becomes ves	elf, elves; loaf, loaves; thief, thieves
Most nouns that end in o	add s	kangaroo, kangaroos; piano, pianos; video, videos
Certain nouns that end in a consonant and o	add es	hero, heroes; potato, potatoes; volcano, volcanoes

The Canadian College of English Language