Great subject! Students learn active voice at the earliest stages of English. Passive voice is usually taught at the pre-intermediate or intermediate levels. However, students should be introduced to passive voice at the earliest stages of English study. Why? To stress the importance of both the verb “To Be” and “Participle 2“ verbs. Why is this important? Both passive and active are used in everyday speech! It is also important that students study all three verb forms at the earliest stages. In other words, students should study verbs in the “Infinitive, Past Simple and Participle 2“ at the earliest stages. Active voice is when the focus is on the subject with a verb. Passive voice is when the focus is on the object with a verb. This is a simple explanation.