Subject-verb agreement is one of the fundamental rules of grammar that every writer and editor must know. It refers to the rule that the subject and the verb in a sentence must agree in number, whether singular or plural. Proper subject-verb agreement is crucial for clear and effective communication, which is particularly important in the age of SEO, where proper grammar plays a significant role in determining a website`s search engine ranking.

Here are 21 rules to keep in mind when it comes to subject-verb agreement:

1. A singular subject requires a singular verb, while a plural subject requires a plural verb.

2. If the subject is singular and ends in “s,” it still requires a singular verb. For example, “The news is shocking.”

3. If the subject is a collective noun (a group of people or things), the verb can be either singular or plural, depending on the writer`s intention. For example, “The team is playing well” or “The team are arguing among themselves.”

4. When using “each” or “every” before a subject, the verb should be singular. For example, “Every student is required to attend the assembly.”

5. When using “neither” or “either,” use a singular verb. For example, “Neither of the boys is wearing a hat.”

6. When using “or” or “nor” to connect two subjects, the verb agrees with the subject closest to it. For example, “Neither the apples nor the oranges are ripe.”

7. When using “not only…but also,” the verb agrees with the subject closest to it. For example, “Not only the writer but also her editor is happy with the final draft.”

8. When using “accompanied by” or “in addition to,” the verb agrees with the subject before the phrase. For example, “The CEO, accompanied by her assistants, is attending the conference.”

9. When using “as well as,” the verb agrees with the subject before the phrase. For example, “The actress, as well as her co-stars, is excited about the premiere.”

10. When using “with,” the verb agrees with the subject before the preposition. For example, “The dog, with its wagging tail, is happy to see its owner.”

11. When using “one of,” the verb agrees with the subject after “of.” For example, “One of the books is missing.”

12. When using “none” before a plural subject, use a plural verb. For example, “None of the students are late.”

13. When using “some” before a plural subject, use a plural verb. For example, “Some of the flowers are blooming.”

14. When using “more than one,” use a singular verb. For example, “More than one car is parked in the driveway.”

15. When using “many a,” use a singular verb. For example, “Many a student has struggled with math.”

16. When using “everybody,” “nobody,” or “someone,” use a singular verb. For example, “Everybody knows the answer.”

17. When using “there” as a dummy subject at the beginning of a sentence, the verb agrees with the subject following the verb. For example, “There are two cats in the garden.”

18. When using a collective noun that refers to a singular unit, use a singular verb. For example, “The class is taking a test.”

19. When using a collective noun that refers to individual members, use a plural verb. For example, “The team are wearing their uniforms.”

20. When using a title followed by a name, use a singular verb. For example, “Dr. Johnson is teaching the class.”

21. When using a pair of subjects joined by “and,” use a plural verb. For example, “The cat and the dog are playing outside.”

In conclusion, subject-verb agreement is an important aspect of good grammar and effective communication. As a professional, it`s crucial to keep these 21 rules in mind to ensure that the content we create is clear, accurate, and optimized for search engine ranking.