English Grammar : article, syntax, verbs conjugation, English spelling

Count and mass nouns

Nouns can typically be divided into two categories: COUNT and MASS nouns. Nouns that are countable (e.g. “one house,” “two houses;” or “one deer,” “two deer” are called “count nouns.” The plural forms of the these nouns are usually made by adding an “s” to the singular forms. For example:

Singular Plural
horse horses
train trains
boy boys
drink drinks

However, some countable nouns have irregular plural forms:

person people
sheep sheep
man men
fish fish
tooth teeth

MASS nouns are things which can't be counted by themselves because they are always treated as a group, volume, mass or quantity. Some common mass nouns are:

liquids: water, oil, gasoline
materials: coal, steel, wood
food: bread, fruit, butter
ideas: love, knowledge, advice

In order to count mass nouns you must use “amount words” or “quantifiers.” Some examples are:
a pound of butter
three baskets of fruit
four slices of bread
two liters of oil
a glass of water
a grain of sand
two pairs of eyeglasses