The vast majority of nouns in the English language are made plural by adding an "s" or "es" to the end of the word. For example, book, apple, house, table, door, cat, bush, boss are just some of the many words that become plural with the simple addition of an "s" or "es" (books, apples, houses, tables, doors, cats, bushes, bosses).
However, certain nouns have irregular plurals which do not behave in this standard way and, even though most irregular plurals follow a pattern, there are always exceptions to watch out for.
The general rule for making a noun plural is that if the word ends in s, x, z, ch or sh, add an "es"
An exception to this rule is if the ch ending is pronounced with a "k" sound you add "s" rather than "es"
If the word ends in a consonant (all letters except a, e, i, o, u) plus "y," then change the "y" to an "i" and add the letters "es"
For all other non-irregular nouns, simply add an "s" to the end of the word
Certain words do not follow the above rules for regular plurals. There are some common types of irregular plurals that occur, and some words simply have no plural form at all.
While it is useful to memorize the common irregular plurals, for many words you simply have to know and understand that it is an irregular plural as a result of speaking and hearing English.
If you are talking about multiple varieties or types of these irregular plurals, you cannot make them plural by adding an "s" or "es" to the end. Instead, you need to make them plural by adding a descriptive phrase. For example:
Certain other nouns have the same plural form as singular form. A large number of animals happen to follow this rule. For example:
In addition to non-count nouns and unchanging nouns, there are several different types of irregular plurals which follow a pattern in the English language.
For most nouns that end in "f" or "fe," you drop the "f" or "fe" and add "ves"
For many words that end in "us," change the "us" to an "i" (especially if it comes from a Latin word). There are exceptions to this rule and it is becoming more acceptable to add "es" instead of changing to "i."
For nouns that end in "o" you add either "s" or "es". (Generally, most nouns ending in "o" just add "s" to make the plural, especially if there's a vowel before the final "o")
For many words that end in "is," change the "is" to an "es"
Nouns that end in "um" often become plural by changing "um" to "a"
Certain words do not add a letter to the end but instead, change the word itself. These words simply need to be memorized. Some examples include:
The best way to learn and understand irregular plurals is to practice speaking the English language, to read a great deal, to pay attention to words and phrases that you see and hear and to assemble a list of words with irregular plurals so you can begin to understand how to make each noun plural correctly.