What is the correct form of the verb in the following sentence: "He _____ running every morning for exercise"?

The correct form of the verb in the sentence "He _____ running every morning for exercise" is "enjoys" because it must agree with the third-person singular subject "He." In English, the present simple tense for third-person singular subjects typically adds an "s" to the base form of the verb. Therefore, "enjoys" correctly conveys that he has a habitual action or a general truth about his daily routine.

In contrast, the other options do not fit properly grammatically in this sentence structure. "Enjoyed" is in the past tense and would imply that he no longer runs every morning. "Enjoy" is in the base form, which does not correspond with a third-person singular subject. "Enjoying" is a participle that indicates an ongoing action but lacks the necessary auxiliary verb that would otherwise form a continuous tense. Thus, "enjoys" is the appropriate choice to accurately communicate the intended meaning.