In the sentence "The runners are running fast," which verb form agrees with the subject?

• A. are running
• B. running
• C. is running
• D. runs

Answer: (A)

The main idea here is how the subject and the verb match in number and tense. The subject “The runners” is plural, so the verb must be in a plural form and, since the sentence describes an action happening right now, it uses the present continuous tense. The correct form is the plural form of “to be” plus the -ing verb: are running. That shows ongoing action and agrees with the plural subject.

The other forms don’t fit for these reasons: just "running" isn’t a complete finite verb on its own in this sentence; "is running" uses the singular form of “to be,” which doesn’t match a plural subject; and "runs" is the simple present form used with singular subjects or third-person singular, not with a plural subject like "runners."