Explain the concept of subject-verb agreement.

Subject-verb agreement is a grammatical concept that refers to the agreement between the subject and the verb in a sentence. In English grammar, the subject is the noun or pronoun that performs the action or is being described, while the verb is the action or state of being in the sentence.

The concept of subject-verb agreement states that the subject and the verb must agree in number and person. This means that a singular subject should be paired with a singular verb, and a plural subject should be paired with a plural verb.

To ensure subject-verb agreement, it is important to consider the following rules:

1. Singular subjects usually take singular verbs, while plural subjects usually take plural verbs. For example:
- The cat sleeps. (singular subject and verb)
- The cats sleep. (plural subject and verb)

2. When the subject is a singular noun or pronoun, the verb should also be singular. For example:
- She runs every morning. (singular subject and verb)
- The book is on the table. (singular subject and verb)

3. When the subject is a plural noun or pronoun, the verb should also be plural. For example:
- They play soccer every weekend. (plural subject and verb)
- The dogs are barking loudly. (plural subject and verb)

4. In sentences with compound subjects joined by "and," the verb should be plural. For example:
- John and Mary are going to the party. (plural subject and verb)

5. In sentences with compound subjects joined by "or" or "nor," the verb should agree with the subject closest to it. For example:
- Neither the cat nor the dogs are allowed on the couch. (plural subject and verb)

6. In sentences with collective nouns, the verb can be singular or plural depending on whether the emphasis is on the group as a whole or the individuals within the group. For example:
- The team is practicing. (singular verb emphasizing the group)
- The team are arguing among themselves. (plural verb emphasizing the individuals)

Overall, subject-verb agreement is crucial for maintaining grammatical correctness and clarity in writing and speaking. By ensuring that the subject and verb agree in number and person, we can effectively convey our intended meaning and avoid confusion.