Concord, also known as agreement, refers to the grammatical principle in which certain parts of a sentence must match or agree with each other in terms of number, gender, person, or case. Here are the key points to understand concord in grammar:

1. Subject-Verb Concord

This is the most common type of concord, ensuring that the subject of a sentence agrees with the verb in number and person.

• Singular Subject with Singular Verb:
  • Example: The cat runs fast.
• Plural Subject with Plural Verb:
  • Example: The cats run fast.

2. Pronoun-Antecedent Concord

Pronouns must agree with their antecedents (the words they replace) in number, gender, and person.

• Singular Antecedent with Singular Pronoun:
  • Example: The student lost her book.
• Plural Antecedent with Plural Pronoun:
  • Example: The students lost their books.

3. Concord of Number

Nouns and pronouns must agree in number with the words they relate to.

• Singular with Singular:
  • Example: Each of the players has his own locker.
• Plural with Plural:
  • Example: All the players have their own lockers.

4. Concord of Person

The verb must agree with the subject in terms of the first, second, or third person.

• First Person:
  • Example: I am happy.
• Second Person:
  • Example: You are happy.
• Third Person:
  • Example: He is happy.

5. Concord of Gender

Pronouns must agree in gender with the nouns they replace.

• Masculine Gender:
  • Example: The boy found his toy.
• Feminine Gender:
  • Example: The girl found her book.
• Neutral Gender:
  • Example: The dog found its bone.

6. Concord in Complex Sentences

Ensuring agreement within complex sentences, especially when clauses are involved.

• Example:
  • The teacher, along with the students, is going on a trip. (The main subject 'teacher' is singular.)

7. Concord of Quantity

Certain expressions of quantity require specific verb agreements.

• Example:
  • A lot of students are coming. (A lot of + plural noun = plural verb)
  • A lot of milk is needed. (A lot of + uncountable noun = singular verb)

Special Cases in Concord

• Collective Nouns: These can take singular or plural verbs based on whether the group is considered as a single unit or as individuals.

  • Singular: The team wins every match.
  • Plural: The team are arguing among themselves.

• Titles of Books, Movies, etc.: These take singular verbs regardless of their form.

  • Example: "The Chronicles of Narnia" is a popular book series.

• Expressions with "and": When subjects are connected by "and" but refer to a single entity, they take a singular verb.

  • Example: Bread and butter is my favorite breakfast.

• Either/Neither with Or/Nor: The verb agrees with the noun or pronoun closest to it.

  • Example: Either the teachers or the principal is going to speak.