Subjects and verbs must agree with each other in number for a sentence to make sense. Even though grammar can be a bit quirky from time to time, there are 20 rules of subject-verb agreement that sum up the topic quite concisely. Most of the concepts of subject-verb agreement are straightforward, but exceptions to the rules can make it more complicated.
For example, would you say, "They are fun" or "They is fun"? Since "they" is plural, you'd opt for the plural form of the verb, "are". Ready to dive into a world where subjects and verbs live in harmony?