This is related to number. A noun that denotes one person or thing is said to have a singular form. For example, the nouns in the first passage (teacher, banker, child, family, and life) are all singular in form. On the contrary, a noun that denotes more than one person or thing is said to have a plural form. For example, all the nouns in the second passage (teachers, children, students, members, and books) are plural in form.
 

The number is a grammatical distinction that tells whether a noun (also a pronoun, verb, or determiner) is singular or plural. There are two numbers in English — the Singular and the Plural.

A. Read the following two passages and notice the forms of the underlined
nouns:

(i)    Mr. Aslam is a teacher. His wife is a banker. They have only one child. Theirs is a small family. They live a happy life.
(ii)    Mr. and Mrs. Hasan are teachers. They have two children. Both of them are students. All the four members of this family are fond of books.

In the first passage, each of the underlined nouns denotes only one person or thing. On the other hand, each underlined noun in the second passage denotes more than one person or thing.
B Plurals are usually formed by adding s, es or ies to the singular form. Look at the following examples.
(i) Singular + s = plural

SingularPlural
boyboys
girlgirls
dogdogs
pagepages
monkeymonkeys

Note: Most nouns are made plural by adding an s to the singular form. 

(ii) Singular + es = plural

SingularPlural
bus buses
kiss  kisses
dish dishes
watchwatches
box boxes

Note: Plurals are formed by adding es when the singular form ends in s, ss, sh, ch, and x.

(iii) Singular + ies = plural
baby    babies
lady    ladies
story    stories
duty    duties
fly    flies

Note: Singular nouns ending in a consonant + y form their plurals by dropping y and adding ies.

C. Plural forms of nouns can also be made in other ways. Notice the following examples:
(i) Singular nouns ending in f/fe form their plurals by dropping f/fe and adding ves:
calf
calves

wives
knives
wife knife
Now write the plural forms of the following nouns:
thief _____________________
leaf    _______________
wolf ______________________
shelf _____________________
life    _______________

(ii) Plurals are often formed by making an internal change of vowels:
foot    feet
tooth    teeth
man    men
Now fill in the following blanks with plurals:
goose ________________
mouse ________________
woman ________________
louse    ___________
 

(iii) Look at the plurals of some compound words:
boy-friend    boy-friends
take-off    take-offs
step-son    step-sons
passer-by    passers-by
looker-on    lookers-on
runner-up    runners-up
father-in-law    fathers-in-law
man-of-war    men-of-war

(iv) Nouns ending in thesis crisis basis diagnosis synopsis have es in the plural:

SingularPlural
thesis
crisis
basis
diagnosis
synopsis
theses
crises
bases
diagnoses
synopses

D. Number Is applicable not only for nouns but also for pronouns, verbs, and determiners. Read the following passage and notice the underlined words:

Karim Is a student of class nine. He Jiinjt friend. We ge to school together by rickshaw. W£ always share our rickshaw fare. In his free time he loves to play badminton while I love to watch movies.
In this passage 'he' and 'we' are pronouns; 'reads', 'is1, 'go' and 'share' are verbs, and 'my* and 'our' are determiners. You can easily guess which of these words are singular and which are plural. Remember, whether a verb Is singular or plural is determined by its subject. A singular subject takes a singular verb and a plural subject takes a plural verb.

Activity 1: Now fill In the gaps In the following sentences:
We have a pet that__________in our house. We_________all very fond of It. My
mother_____________care of it. It________to eat fish and milk. It________us
by killing_________
 

Activity 2: Rewrite the following passage changing the singular words Into their plural forms:
As you are my friend, you can borrow this book from me. But you should return it within a week. You should not tell a lie to me. I hate a liar. I also hate a person who breaks a promise.