Improve_Your_Written_English

Changing ‘y’ to ‘i’

If a noun ends in ‘y’, and there is a consonant before it, a
plural is formed by changing the ‘y’ into an ‘i’ and adding
‘-es’:

berry – berries

company – companies

lady – ladies

nappy – nappies

If the ‘y’ is preceded by another vowel, an ‘s’ only is added:

covey – coveys

monkey – monkeys

donkey – donkeys

Adding ‘es’ or ‘s’

If a noun ends in ‘o’ and a consonant precedes the ‘o’, ‘-es’ is
added to form a plural:

hero – heroes

potato – potatoes

tomato – tomatoes

If there is a vowel before the ‘o’, an ‘s’ only is added:

patio – patios

studio – studios

zoo – zoos

It would be difficult to add an ‘s’ only to some words because
it would be impossible to pronounce them. These are words
that end in ‘ch’, ‘sh’, ‘s’, ‘x’ and ‘z’. In this case an ‘e’ has to
be added before the ‘s’:

54 / PART ONE: THE BASICS