Subject and Verb Agreements

A Verb must agree with its subject in person and number; i.e,
    i) Singular subjects take singular verbs.
    ii) Plural subjects take plural verbs.

SINGULAR SUBJECTS

Rule 1. Singular pronouns require singular verbs. These pronouns are singular: each, everyone, everybody, anyone, anybody, someone, somebody, no one, nobody, one, many a, one, another, anything, either, neither.
 •  Someone have spilled the coffee here. (Wrong)
 •  Someone has spilled the coffee here. (Right)
 •  Each of the boys receive a book. (Wrong)
 •  Each of the boys receives a book. (Right)
 •  Everyone are concerned about corruption. (Wrong)
 •  Everyone is concerned about corruption. (Right)
 •  Neither of the students have finished the assignment. (Wrong)
 •  Neither of the students have finished the assignment. (Right)

Rule 2. Compound subjects (joined by "and") that is preceded by "many a", "every", or "each" are singular and take singular verbs.
 •  Many a boy and girl have great ambitions. (Wrong)
 •  Many a boy and girl has great ambitions. (Right)
 •  Each father and mother have certain responsibilities.  (Wrong)
 •  Each father and mother has certain responsibilities.  (Right)
 •  Every boy and girl welcome the teacher. (Wrong)
 •  Every boy and girl welcomes the teacher. (Right)

Rule 3. For nouns which are plural in form but singular in meaning, use a singular verb. These nouns are:
a. Academic subjects: mathematics, physics, economics, statistics...
 •  Mathematics are a difficult subject. (Wrong)
 •  Mathematics is a difficult subject. (Right)
b. Names of diseases: measles, mumps, herpes ...
 •  Measles are sometimes serious. (Wrong)
 •  Measles is sometimes serious. (Right)
c. Title of a book, song, play, film, painting, or other such work.
 •  Romeo and Juliet are an interesting novel. (Wrong)
 •  Romeo and Juliet is an interesting novel. (Right)
 •  Star Wars were very famous. (Wrong)
 •  Star Wars was very famous. (Right)
d. Expression of amount
 •  Fifty dollars seem high for that radio. (Wrong)
 •  Fifty dollars seems high for that radio. (Right)
 •  Two weeks is not enough time for this project. (Wrong)
 •  Two weeks are not enough time for this project. (Right)
 •  Three meters of cloth make a dress for my size. (Wrong)
 •  Three meters of cloth makes a dress for my size. (Right)

Rule 4. Impersonal pronoun "it" at the beginning of a sentence is followed by a singular verb.
 • It is his suggestions that finally take precedence.
 • It is so hot.

Rule 5. A gerunds functioning as subject is singular and takes a singular verb. 
 • Swimming is my favorite sport.
 • Eating fast foods is not good for health.


PLURAL SUBJECTS

Rule 6. A compound subject that is joined by "and" is plural and takes a plural verb.
 •  A man and his son is talking. (Wrong)
 •  A man and his son are talking. (Right)
 •  Thinking and practicing helps students to learn more. (Wrong)
 •  Thinking and practicing help students to learn more. (Right)

Rule 7. The plural indefinite pronouns such as all, both, several, few, many... take plural verbs.
 •  Few has come and attended however. (Wrong)
 •  Few have come and attended however. (Right)
 •  Both of us is students. (Wrong)
 •  Both of us are students. (Right)
 •  Many is afraid to take all annual leave. (Wrong)
 •  Many are afraid to take all annual leave. (Right)

Rule 8. Nouns such as scissors, refreshments, clothes, pliers, etc. are always plural and take plural verbs.
 •  Refreshments is now served at the canteen. (Wrong)
 •  Refreshments are now served at the canteen. (Right)
 •  The pliers is on the table. (Wrong)
 •  The pliers are on the table. (Right)

Rule 9. Adjectives used as a nouns are considered plural.
*The old need some recognition to feel that they are belong.
 •  The intelligent is not arrogant. (Wrong)
 •  The intelligent are not arrogant. (Right)
 •  The old was evacuated from the building. (Wrong)
 •  The old were evacuated from the building. (Right)
 •  The rich is privileged. (Wrong)
 •  The rich are privileged. (Right)


EITHER SINGULAR OR PLURAL SUBJECTS 

Rule 10. "Here" and "there" that begin the sentence are not subjects; verb must agree with a noun standing after the verb.
 •  Here is the books you want. (Wrong)
 •  Here are the books you want. (Right)
 •  There is trees in your backyard. (Wrong)
 •  There are trees in your backyard. (Right)
 •  There are a bird next to the tree. (Wrong)
 •  There is a bird next to the tree. (Right)

Rule 11. A prepositional phrase that follows the subject does not affect the number of the verb.
 •  A combination of factors were the cause of the plane crash. (Wrong)
 •  A combination of factors were the cause of the plane crash. (Right)
 •  Tom as well as his brother are invited to the party. (Wrong)
 •  Tom as well as his brother are invited to the party. (Wrong)
 •  The boys as well as his classmates is going to visit the museum. (Wrong)
 •  The boys as well as his classmates are going to visit the museum. (Right)
 •  The colors of the rainbow is beautiful. (Wrong)
 •  The colors of the rainbow are beautiful. (Right)

Rule 12. A collective noun as the subject is singular if the whole group is referred to, but it is plural if the individuals of the group are considered.
 •  The team fights for victory. (Singular)
 •  The team play cooperatively. (Plural)
 •  The committee disagrees on a chairperson. (Singular)
 •  The committee disagree on some challenging problems. (Plural)

Rule 13.  If two subjects are joined by "or", "either ... or", "neither . . . nor", "not only... but also", the verb agrees with the subject that is close to the verb.
 •  Either a dog or a cat makes a good pet.
 •  Either Jim or his friends are bringing the cake. 
 •  Neither the class monitor nor his friends have finished homework.
 •  Neither Tom nor the twins like to travel.
 •  Not only the manager and salesman is busy at the moment.
 •  Not only the manager and salesmen are presenting a new products.

Rule 14. Some indefinite pronouns may be to singular or plural depending on the following nouns. These pronouns are:  all, any, more, most, none, some.
 •  Some of the students were absent.
 •  Some of money is spent.  •  All of the people are happy.
 •  All of the effort has been made.

Rule 15. Fractions are singular or plural depending upon nouns in the of phrase.
• Three-fourths of the roof is painted.
• Three-fourths of the members are here.
• All the girls were eager to have a beach party.
• All the food was gone.
• One half of the class misses out the first period.

Rule 16. When the word number is used in the sense of "many" it is plural; when it refers to an arithmetical number, it is singular.
 •  A number of people are waiting outside.
 •  The number of people who have subscribed is surprisingly small.

Rule 17. Be careful of the plurals of foreign nouns. Some nouns retain the plural forms of the foreign language from which they have been taken. Though they may look like singular nouns, they are plural and require plural verbs.These word are: crisis (crises), phenomenon (phenomena), alumnus (alumni), datum (data), criterion (criteria), fungus (fungi)...
 •  The fungus has been identified.
 •  The selection criteria have been publicly announced.
 •  The financial crisis is not over yet.
 •  Crises are common in a war-torn country.

Rule 18. Verb agrees with a subject that follows the verb.
 •  At the bottom of the stairs stands a statue.
 •  Here comes the newest members of football squad.

Rule 19.  If one subject is used affirmatively and the other negatively, the verb agrees with the subject that is used affirmatively.
 •  He, not I, is responsible.
 •  You, not I, are accountable for the loss of the book.

Rule 20. A relative pronoun {who, which, that) may be singular or plural depending upon the word to which the pronoun refers.
  •  He is the man who writes/write the reports.
  •  The students who come from provinces might have lots of difficulties..