Video narration
Why is it "The dog runs," but "The dogs run"? They look almost alike, but one small verb ending changes. In "The dog runs," the subject-the one the sentence is about-is "the dog." The verb, the action word, is "runs." In "The dogs run," "the dogs" is the subject, and "run" is the verb. The subject tells you whether you mean one dog or more than one. Here's the key: the verb form follows its subject. One dog runs; more than one dog run. That fit between subject and verb is called subject-verb agreement: choosing a verb form that matches who or what the sentence is about. To check a sentence, find who or what it's about, then see whether the action word fits. That's why the verb matches its subject: one dog runs, but the dogs run.