Singular and plural relate to a property of the noun. That property is called 'number. Number' means counting: 1,2,3,...etc. In English grammar too it is related to counting. People refer to it also as 'grammatical number.'
What is Number in Grammar?
Number is a form of the noun, by which we know whether the name (noun) refers to one of something or more than one of that thing.
When the thing named is one, we say that the noun has a Singular number; when it is more than one, we say that the noun has a Plural number.
Since mass nouns cannot be counted, they have no plural.
The Singular and the Plural forms of the noun are usually similar. This is because a plural is formed out of a singular. In most cases this is done by making a small change in the spelling or sound.
Add 'es' for words ending in 'o', 'x', 'ch' or 'sh'.
3
photo, dynamo, piano, stomach
photos, dynamos, pianos, stomachs
Exceptions to no. 2 above. Add only 's'. The first three words are commonly used short forms for photograph, dynamoelectric, pianoforte. In the word stomach, the 'ch' is pronounced as 'k'
4
bamboo, igloo, cuckoo
bamboos, igloos, cuckoos
Add 's' for words ending in 'oo'
5
boy, donkey, day, key, bay, way, toy,
boys, donkeys, days, keys, bays, ways, toys
Add 's' towords ending in 'y' before which comes a vowel letter.
6
lady, lorry, body, berry, story
ladies, lorries, bodies, berries, stories
Add 'es' after changing the 'y' into 'i'. This is for words which end in 'y' and have a consonant letter coming before the 'y'.
7
leaf, wife, life, thief, sheaf
leaves, wives, lives, thieves, sheaves
Change the 'f' or 'fe' ending of these words into 'v' and then add 'es'.
8
brief, chief, roof, belief
briefs, chiefs, roofs, beliefs
These words are exceptions to the ones given in 7 above.
9
scarf, hoof
scarves or scarfs, hooves or hoofs
Both forms of plural (nos. 7 and 8 above) can be used for these words.
10
man, tooth, goose, foot
men, teeth, geese, feet
The vowel sound (between two consonant sounds) is changed to form the plural.
11
louse, mouse
lice, mice
The same rule as in 10 above, except that the last consonant (sound) has also its spelling changed.
12
deer, sheep
deer, sheep
The plural is the same as the singular.
13
hundred, thousand, million
(two) hundred, (five) thousand, (seven) million OR hundreds (of trees), thousands (of people), millions (of stars).
When a number comes before these words, the plural is the same as the singular. At other times, we can have the plural form with an 's'.
sons-in-law, commanders-in-chief, BUT grand-parents, step-daughters, AND men-servants
In compound words: The change may be in the first part of the word, or in the last. Sometimes both parts change. These changes depend mostly on the meaning of the word.
The Singular and Plural forms of nouns are important not only because of meaning. They are important also because the verb in a sentence depends upon the grammatical number of the noun in the subject of a sentence.
