As seen in this sentence, the passive voice is used to indicate that something is being done to a subject by an agent. It's passive because the subject is being acted upon, rather than acting as in the active voice.
(fue) with which learners are more familiar; second, that MRNS use a more frequent passive voice construction, the reflexive passive, also known as morphological passive or se-passive; third, that the verbal passive is not common in oral communication; and, lastly, that the imperfect tense is...