Of all the grammatical rules, passive and active voice seems to plague writers the most. Some people, no matter hard they try, struggle to discern the difference between passive and active sentences. Learning to do so, however, and knowing where to use them, can boost clarity and purpose in your writing.

The Active Voice

In a sentence with active voice, the subject, the noun that performs an action, comes before the verb. The object, the noun that receives that action of the verb, comes after the verb. For example, the subject in the sentence “The bear ate the fish” is “bear” because the bear is performing the action - - it is “eating.” The fish, because it is receiving the action, or being eaten, is the object. The formula for an active sentence is as follows: S+V+O. An active sentence does not require an object, though. “The bear ate” is also active, and follows the formula S+V.

The Passive Voice

The passive voice follows a reverse pattern, O+V+S, although it does not require a subject and can form the pattern O+V. In a passive sentence, the object precedes the verb and the subject follows the verb. To create such a sentence construction, a writer has to add the verb “to be” and the preposition “by,” if the sentence includes an object. For instance, “The fish was eaten by the bear” is passive because the object, “fish” comes first, then the verb “was eaten” and finally the subject, “bear.” Even though bear comes last in this sentence, because it is performing the eating, it is still the subject of the verb. The fish never does anything; it is only passively performed upon.

Advantages of the Active Voice

Many writing instructors and high school teachers warn their students to stay away from passive voice at all costs, and they are mostly right. Firstly, passive sentences are wordier, and effective writing strives for conciseness. “The bear ate the fish” contains five words, while “The fish was eaten by the bear” contains seven. Secondly, beginning with the subject sounds more direct and dramatic. Instead of a teacher asking a student “Why was your paper not handed in by you?”, demanding “Why didn’t you hand in your paper?” sounds more confrontational and authoritative. Thirdly, passive voice construction, because it does not require a subject, raises issues of accountability. A government can dodge responsibility by reporting “Fiscal spending was exceeded and is now being investigated,” a sentence that contains two passive constructions. The sentence does not identify who did the “exceeding” and who is doing the “investigating.”

Advantages of the Passive Voice

At times, however, writers may find avoiding the passive voice impossible. When the police don’t know who committed a crime, unless the newspaper explains the occurrence in passive voice, there is no other way of reporting the event: “A man was murdered this morning near King and Main.” If the performer of an action does not contribute significance to a writer’s point, she can use passive voice: “I’m late because I accidentally went into the wrong room where a conference was being held.” Who was holding the conference is unimportant. A documentary about electricity might begin with “Electricity was first seen by Egyptians in fish,” because electricity is the topic of the documentary, and not Egyptians. Sometimes lab reports use the passive voice: “The beaker was filled with the corrosive solution and then the lid was tightly fitted on.”