A Word about the Passive Voice

Although LRS generally avoids traditional school grammar, you need to know the difference between active and passive voice. You have probably been told by English teachers, "Always use active verbs." That's not a useful rule. Passive verbs can create problems for your reader if you use them at the wrong time — if, for example, a passive verb leads you to hide the agents of actions at the end of sentences or, worse, to drop them out altogether. But the passive voice exists for good and useful reasons. You can also create problems for your reader if you use active verbs instead of passive ones at the wrong time.

For now, remember that readers can follow your story most easily when you use the active voice to say who's doing what. In the session on Topics, we'll give you a simple principle for deciding when to use the passive voice most effectively. 

Definition: Active Voice
In the active voice, the agent of the action is the subject of the sentence, and the receiver or goal of the action (the action's object) follows the verb.
subject verb object
Some cop gave me a ticket.
agent action goal
subject verb object
The attorney forced Dr. Smith to acknowledge his mistake.
agent action goal
Definition: Passive Voice
You can tell whether your verbs are passive in two ways. First, in passive voice the receiver or goal of the action is the subject of the sentence and the agent appears, if at all, in a prepositional phrase beginning with by:
subject verb by-phrase
A ticket was given to me by some cop.
goal action agent
subject verb by-phrase
Dr. Smith was forced by the attorney

to acknowledge
his mistake.
goal action agent

Second, in passive voice the verb includes a form of "be" and the main verb is in its participle form:

A ticket was given to me by some cop.

Dr. Smith was forced to acknowledge his mistake by the attorney.

Once your verb is in the passive voice, you can drop the agent out of the picture entirely:

Dr. Smith was forced to acknowledge his mistake by the attorney.
Dr. Smith was forced to acknowledge his mistake [ ].

The Passive Voice Can Have Negative Consequences. . .

When you use passive verbs where you should use active ones, you're more likely to hide crucial actions in nominalizations and bury or omit the agents of those actions:

If this objective can not be met with the current documentation, then REVISION and IMPROVEMENT of the manual are needed.

If users can not meet this objective with the current documentation, then the company will need to revise and improve its manual.

. . . But There Are Some Good Reasons To Use It

Professional writers often make strategic use of the passive voice:

(1) to avoid a long subject.

You might use the passive voice when you need a lot of words to name the agent and you don't want to have a long subject. Even though this tends to hide the agent, shorter subjects generally make clearer sentences.

Darwin's genius is illuminated by hundreds of letters, both personal and scientific, to scores of recipients, including leading scientific figures. Mendel, however, is represented by only ten letters to the botanist Karl Nageli and a handful to his mother, sister, brother-in-law, and nephew.

(2) to avoid naming the agent.

You may decide to use passive voice when you don't know who did it:

Mrs. Peacock was murdered at 6:00 PM last night in the conservatory.

You may also use the passive voice when you don't want to say who did it because you don't want to assign (or admit) responsibility. Kids learn this early:

The glass was broken.

And professional writers use this strategy all the time. Here's a sentence from a press release by a company whose employee caused a fire because he was negligent:

The loading line connected to tank car 96 was disconnected prematurely, allowing the release of highly flammable vinyl chloride. . . .

(3) to shift the focus from the agent to another character

You might use the passive voice when you and your readers don't care who the agent of the action might be:

At the trial Dr. Smith was forced to acknowledge that the report was more reliable than his own diagnosis.

If you are talking about Dr. Smith and his problems, you probably don't care about the anonymous trial attorney who made him acknowledge his errors. You use passive voice to put the main character on center stage.

In scientific and technical prose, it's often the case that neither you nor your reader care about or want to focus on who's doing the action. For instance, we may know generally who performed the action but don't care about the identity of the specific person:

The prosthesis was debrided using a lateral transtrochantic approach.

Someone on the operating team did this, but unless we're talking a malpractice suit, we don't care which one. Likewise, you may be talking about a procedure you performed, an object you studied, or an apparatus you designed, and you want to tell its story rather than your own:

The gamma-ray spectra of the specimens were measured. . . . The surface characteristics were determined. . . . The specimens were mounted. . . .

In this case using active voice would focus too much on the author rather than the procedure: "I measured. . . . I determined. . . . I mounted. . . ."