Thou shalt not use the passive voice!
How often have you heard this commandment? Almost as often, I'd bet, as “Show, don't tell”. However, like most things in life, it's not that simple. The passive voice is a legitimate English construction. It is perfectly grammatical and exists for very good reasons.
I've found that many authors, and even editors, are confused about the passive voice. Recently I had an editor object to one of my sentences because she believed it was passive. The sentence had the form “she had spoken to her friend before departing”. This is not a passive sentence but she apparently thought it was, presumably because it includes a so-called helping verb (“had”). So before I go further and defend the passive (under certain circumstances), let me try to clarify the definition of passive voice.
A sentence is passive voice if the grammatical subject of the sentence is the logical or semantic object, that is, the recipient of an action rather than the actor.
Maybe this doesn't help. Let me put it more colloquially. In a passive sentence, the subject of the sentence doesn't “do” anything; it is “done to”.
Some examples may make things clearer:
(1) Active: The dog bites me. Passive: I am bitten [by the dog]. (2) Active: The vampire licked the tender flesh below her earlobe. Passive: The tender flesh below her earlobe was licked [by the vampire]. (3) Active: He had kissed her tenderly before he climbed onto his horse. Passive: She had been kissed tenderly by him before he climbed onto his horse. (4) Active: I will eat my vegetables. Passive: My vegetables will be eaten [by me].
In each case, the passive version reverses the active version, making the direct object be the subject, and optionally adding the former subject as the object of the preposition “by”.
The predicate in a passive sentence is some form of the verb to be followed by the past participle of the verb expressing the action. For regular verbs, the past participle ends in “ed” and has the same form as the simple past:
licked kissed prodded checkmated discombobulated
Irregular verbs, however, often have special forms for the past participle:
eaten bitten torn shown overgrown
By the way, only transitive verbs can be involved in passive sentences. A transitive verb is one that requires a direct object. (Some verbs can be used in both transitive and intransitive situations.) If there's no possibility of a direct object, then clearly the object can't be made into a subject.
Note that just because a sentence includes a form of the verb to be does not mean it is passive. For example, the following sentences are all active voice:
I am an erotic romance author. I was hungry. I had been waiting for the bus for nearly half an hour.
Notice also that the question of tense (that is, at what time the action occurred) is independent of whether a sentence is active or passive. In my first four examples, (1) is present tense, (2) is simple past, (3) is past perfect and (4) is future. In the passive version, the form of the verb to be determines the tense.
So now that we know what passive voice is (and is not!), why is it so maligned? The primary reason so many books advise against using the passive is the fact that passive sentences can reduce the impact of an action. Active sentences are shorter, more direct and more dynamic than passive ones. Using active as opposed to passive voice is akin to choosing strong, specific verbs over weak, general ones: “stumbled”, “sauntered”, or “strolled” instead of “walked”, for example.
In fact, psychological research has demonstrated that passive sentences are more difficult to understand than active sentences. This makes sense. In an active sentence, the grammar supports and provides clues to the underlying meaning. In a passive sentence, grammar and meaning conflict.
Given these results, why would you ever want to use the passive voice? There are at least three situations in which the passive is desirable or even necessary:
1. The true actor – the logical subject of the action – is unknown.
As the door slid closed, I was knocked on the head so hard that I saw stars. Many articles have been written about the perils of the passive voice.
2. You deliberately want to focus attention on the recipient of the action, because this is your current POV character.
Henrietta had been wooed by every eligible bachelor in the county, but she despised them all. Buck was bruised and battered by the gang's weapons, but he refused to give up.
3. You deliberately choose an indirect mode of expression for stylistic reasons.
Professor Rogers was a man of well-established habits, delicate sensibilities and refined tastes. He was enthralled by the soaring harmonies of Mozart's Requiem and intrigued by the challenging arguments of Sartre. Rogers was confused when students insisted on sending him email. In his world view, words should be committed to paper and vouchsafed to the Royal Mail for delivery.
In the third example, the repeated use of passive voice reinforces the presentation of Professor Rogers as a fussy, overly-intellectual character, the exact opposite of a man of action. Even though this paragraph is not in fact in the Professor's words, it sounds like something he might have written.
In summary, there are sometimes good reasons for adopting the passive voice. As a general rule, however, active voice tends to be more readable and engaging. What is is important is to be aware of your choices in this regard. If the passive seems right for the situation, don't be shy about using it. Recognize the passive when it pops up in your writing and make deliberate decisions based on knowledge and craft.