In English, plural forms are used to refer to quantities of a noun other than one, that is when there are zero, two, or more of the noun. There are two types of nouns: countable nouns, which can be counted as individual units (e.g., dogs), and uncountable nouns, which represent uncountable things such as concepts, liquids, time, money, and substances such as rice and sand. Countable nouns are pluralized by adding the suffix -s, or -es if the noun ends in -s, -x, -z, -sh, or -ch. Uncountable nouns are usually pluralized by using noun quantifiers, like a little or a large amount of, as shown in the table below. Take note that some nouns, such as cake, coffee, and fish, for example, can function as both countable and uncountable nouns, depending on their usage.
| Countable Nouns | Quantifiers for Countable Nouns |
|---|---|
| mosquito, phone, friend, report, computer, cake, lake, river, table, student, university | many, some, a few, few, several, a number of |
| Uncountable Nouns | Quantifiers for Uncountable Nouns |
| anger, stress, advice, motivation, air, sleep, rice, sunshine, weather, gasoline, courage, ink | a little, little, much, a great deal of, a bit of, a large amount of |
Some quantifiers, such as a lot of, some, and plenty of, are used for both countable and uncountable nouns. However, care must be taken to use the correct subject-verb agreement. Compare the following:
Finally, please be aware of nouns with irregular plural forms, such as those in the table below.
| Irregular Plural Forms (words with oo or ou) |
|---|
| mouse (mice), goose (geese), tooth (teeth), foot (feet) |
| Irregular Plural Forms (words ending in -f) |
| knife (knives), wife (wives), leaf (leaves), calf (calves), scarf (scarves) |
| Irregular Plural Forms (words ending in -is) |
| hypothesis (hypotheses), crisis (crises), analysis (analyses), thesis (theses) |
| Irregular Plural Forms (plural forms ending in -a) |
| datum (data), criterion (criteria), phenomenon (phenomena), bacterium (bacteria), curriculum (curricula) |