A tribe of goats gathered around the village elder, who began to teach them the ways of subject-verb agreement.
The elder explained that a subject and verb must agree in number, or else the sentence will be as confusing as a goat in a maze.
For example, "The cat" is a singular subject, so it must be paired with the singular verb "is."
See a singular subject example.
But what about plural subjects? The elder asked the tribe, "If you have many goats, what verb form do you use?"
The tribe thought for a moment, and the elder replied, "You use the plural verb form, of course!"
And what about irregular verb forms? The elder chuckled and said, "Those are like the goats that refuse to follow the rules."