Understanding the difference between active and passive voice enhances the writer’s craft. The voice of a verb indicates whether a subject is acting or being acted upon. Active voice makes a strong statement. Passive voice is generally vague and undesirable in a well-constructed paper; hence, it should be used sparingly.
One way to determine whether a sentence is active or passive is to ask the question, “Who did it?” If the subject of the sentence has performed the action, then it is probably active voice. In the example below, the subject of the sentence (Julie) performed an action (tripped) on the object (the professor).
Julie tripped the professor. (ACTIVE VOICE)
Here are more examples of active voice. Notice that the action of the sentence progresses to the right:
My teacher always gives difficult assignments.
I inserted the glass tubing into the rubber stopper.
In each of these sentences, you should ask yourself, “Who tripped?” “Who gives?” and “Who inserted?” Since the sentences are in active voice, the answer to these questions will be the subject of the sentence (Julie, my teacher and I).
In passive voice, the subject is acted upon by someone or something else; therefore, the subject of the sentence does not provide the answer to the question: “Who did it?” Instead, the person or thing that performs the action is either absent from the sentence or sandwiched into a prepositional phrase that begins with the word by. In the following example, the subject (the professor) is acted upon (tripped) by an outside force (Julie).
The professor was tripped by Julie. (PASSIVE VOICE)
Look at these examples of passive voice and notice how the action of the sentences moves toward the left:
Difficult assignments are always given by my teacher.
The glass tubing was inserted into the rubber stopper.
(Note that in this sentence the person performing the action has been eliminated entirely)
When Should I Use Passive Voice?
Active voice tends to be more direct and less wordy than passive voice, so in most cases, you should choose an active voice construction over a passive one. However, in some circumstances, passive voice is actually more effective than active voice. Writers need to know what to do when these situations occur.
Use passive voice for emphasis:
Compare the following two sentences:
The president of the corporation also witnessed the brash theft. (ACTIVE)
The brash theft was also witnessed by the president of the corporation. (PASSIVE)
Both of the above sentences relay the same meaning (i.e. that a theft has occurred and that the president has witnessed it), but each sentence has a different emphasis. With active voice, the focus is on the actor – in this case, the president of the corporation. Use of the passive voice shifts the focus from the person performing the action to the person or thing that is acted upon (the brash theft).
One instance in which passive voice can be more effective than active voice is when the thing being acted upon is more important than the actor. As mentioned above, passive voice shifts attention from the actor to the thing being acted upon. Thus, when you want to highlight the thing being acted upon, passive voice becomes a tool that will help you do this. Consider the following example of an active voice construction:
Some explorers found the long-lost Ark of the Covenant.
The active voice in this sentence puts the emphasis on the explorers rather than on the Ark of the Covenant. However, the Ark of the Covenant is probably of more interest to the reader than the explorers are; by changing the sentence to passive voice, you can more accurately reflect the relative importance of the sentence’s components:
The long-lost Ark of the Covenant was found by some explorers.
Use passive voice to eliminate the actor:
Passive voice is also useful when the actors are either unknown or so unimportant that you can eliminate them from the sentence entirely. In the previous example, the explorers are of little interest to the reader, so you can leave them out of the sentence:
The long-lost Ark of the Covenant was found.
Use passive voice to achieve objectivity:
Another time when you should choose passive over active voice is when you are writing something in which objectivity is especially important. For instance, in most scientific reports, the general practice is to avoid mentioning yourself in first person. By using passive voice, this is possible. Compare these two sentences:
I mixed the hydrochloric acid with 25 grams of zinc pellets. (ACTIVE)
The hydrochloric acid was mixed by me with 25 grams of zinc pellets. (PASSIVE)
In passive voice, the actor (in this sentence “me”) becomes superfluous, and you can eliminate the actor entirely, giving your paper a greater semblance of objectivity.
Checking For Passive Voice
Get into the habit of reading over what you have written to check for passive voice. Unless you have a valid reason for using the passive voice (as described above), try to change your passive constructions to active ones. Finding passive voice constructions in your writing involves searching for two or three key elements.
Passive voice always includes a form of the verb be (such as am, is, are, was, were, have been, will be, etc.)
This verb form of be is always followed by the past participle of another verb (generally formed by adding –d or –ed to the simple tense). For instance, the past participle of the verb to master is simply mastered.
A final clue in identifying passive constructions is that they often (though not always) include the doer of the sentence preceded by the word by. The following sentence demonstrates all three elements of passive voice.
This subject has been mastered by me.
Reference: Strunk, Wiliam Jr., and E. B. White. The Elements of Style. 4th ed., Allyn and Bacon, 2000.
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