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||Some experiences can be funny.|
|Milk contains calcium.||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||Two bags of apples|
|One cookie||A box of cookies|
|milk||Two cartons of milk|
|sugar||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,
|Money||dollars, bills, fives, cents, dimes, coins|
|Time||years, months, days, hours, minutes|
|Clothing||dresses, pants, shirts, socks, shoes|
|Furniture||Tables, chairs, sofas, lamps|
|Luggage||suitcases, briefcases, bags, carry-ons|