Explain the concept of active and passive voice.

Active and passive voice are two different ways of constructing sentences in English. In active voice, the subject of the sentence performs the action, while in passive voice, the subject receives the action.

In active voice, the sentence structure typically follows the pattern of subject + verb + object. For example, "John ate the apple." Here, "John" is the subject, "ate" is the verb, and "the apple" is the object.

In passive voice, the sentence structure is reversed, and the object of the active sentence becomes the subject. The verb is then followed by the auxiliary verb "be" and the past participle of the main verb. For example, "The apple was eaten by John." Here, "The apple" is the subject, "was eaten" is the verb phrase, and "by John" indicates the agent.

The choice between active and passive voice depends on the emphasis and clarity desired in a sentence. Active voice is generally preferred as it is more direct, concise, and engaging. Passive voice is used when the focus is on the receiver of the action or when the doer of the action is unknown or less important.