Nouns are words that refer to people, places, things and concepts. In English nouns can refer to one item (singular) or more than one item (plural). An 's' or 'es' is added to the end of most nouns when referring to more than one of that item. A few nouns have irregular plural forms.

the boat
the boats
a boat
some boats
the apple
an apple
some apples
An Apple Apples

The following table shows the plural form of some common English nouns.

Singular Plural
boat boats
book books
course courses
match matches
valley valleys
sky skies
child children
man men
woman women
mouse mice
foot feet
tooth teeth
fish fish
Sailboat Sailboats
Box Boxes