Which of the following is a non-finite verb form?

• A. Finite form
• B. Infinitive
• C. Past tense
• D. Third person singular

Answer: (B)

Non-finite verb forms don’t show time, person, or number, and they can’t carry a tense by themselves. The infinitive fits this because it uses to plus the base verb (for example, to eat) and does not mark tense or subject. Finite forms, like past tense or third person singular, carry tense or agreement and change form to reflect time or who is doing the action. The option labeled finite form isn’t itself a verb form, so it isn’t the non-finite option. So the non-finite form here is the infinitive.