Better sentence-writing in 30 minutes a day - Dianna Campbell 1995

Acceptable passive sentences
Passive sentences
Revising sentences

Like faulty parallelism, unnecessary passive sentences are a source of awkwardness in the writing of many students.

You know that the word passive ordinarily means inactive. People are called passive if they wait for things to happen instead of making them happen. Passive sentences are somewhat similar. A passive sentence is not technically wrong like a run-on or a fragment, but it’s relatively weak, flat, and dead. The subject of a passive sentence does not act; it is acted upon.

Here is an example:

1. (a) The position of poet laureate of the United States is currently held by Rita Dove.

Doesn’t that sentence sound awkward? Why use the word position as the subject? Wouldn’t Rita Dove be a more natural choice for a subject? After all, she is the one who is doing something. Here’s an active rewrite of the sentence:

1. (b) Rita Dove currently holds the position of poet laureate of the United States.

Here’s another passive sentence:

2. (a) In some of Sir Arthur Conan Doyle’s stories, the violin is occasionally played by Sherlock Holmes.

An active rewrite is this:

2. (b) Sherlock Holmes occasionally plays the violin in some of Sir Arthur Conan Doyle’s stories.

Acceptable passive sentences

Sometimes passive sentences are all right. For instance, it’s fine to use a passive sentence if you don’t know who did a certain action. For example, it would be perfectly logical to write, “The music was written in the seventeenth century” if you didn’t know who composed the piece. Passive sentences might also be written about an anonymous poem, a purse stolen by an unidentified person, and so forth.

Another valid reason for using a passive sentence is the writer’s desire to place emphasis on a certain area. For example, look at these sentences, each of which is passive for a good reason:

(a) The pterodactyl, a flying dinosaur, was discovered by O.C. Marsh in 1871.

(b) The ancient city of Troy, which for centuries was thought to be purely mythical, was discovered by Heinrich Schliemann.

In each example, the writer might have thought that the thing discovered—in one case, the pterodactyl and in the other, the city of Troy—was of greater historical importance than the person who discovered it. That value judgment then would have led the writer to put the discovery rather than the discoverer in the subject position. Certainly, another writer, perhaps with a different emphasis in mind, could have made O.C. Marsh and Heinrich Schliemann the subjects. The point is that it’s all right to use a passive sentence if you have a valid reason for it.

Here is one more example of an acceptable passive sentence:

(c) The water in and around Minamata, Japan, had been completely contaminated, and many children from the area were born with severe birth defects as a result of the mercury their mothers had ingested.

The first clause—The water in and around Minamata, Japan, had been completely contaminated—is passive, but there may be a good reason for this construction. Perhaps the writer is not concerned at this point with the question of who contaminated the water, and wants instead to emphasize the simple fact that the water was contaminated.