Count nouns have two forms: singular and plural. They can be used with numbers and quantifying expressions such as many, several, and few.
One potato
two potatoes
several potatoes
few potatoes
When used as subjects in present tense sentences, count nouns require the ?s form of the verb in the singular and the base form of the verb in the plural.
The dog sleeps.
The dogs sleep.
The bear has large claws.
Non-count nouns have only one form. When used as subjects in present tense sentences, non-count nouns require the ?s form of the verb.
Juice contains many vitamins.
Honesty is the best policy.
Some nouns can be either count or non-count.
Job experience is essential.
Milk contains calcium.
Some experiences can be funny.
Two milks, please. (informal)
Both count and non-count nouns can be quantified. That is, they can be used with expressions which divide them into parts or groups which can be counted. For example,
Two apples One cookie
milk sugar
Two bags of apples A box of cookies
Two cartons of milk A cup of sugar
Sometimes a non-count noun is used to indicate a ?group? of items, whereas individual items within the group are countable. For example,
