The reason we are devoting nearly an entire section to tips on removing the passive voice from your writing is that it's both a very common flaw and very easily correctable. Within this section we also will explain how to choose more active language even when passive voice is not involved.
Passive voice occurs when the subject and object of an action are inverted, so the subject is the recipient of the act instead of its performer. For example:
PASSIVE: The man was bitten by the dog.
ACTIVE: The dog bit the man.
PASSIVE: I was told by my teacher to come at noon.
ACTIVE: My teacher told me to come at noon.
Note that the word "by" is present in these two examples. A sentence can be passive without the word "by," but it is always at least implied. For example: "I was given bad directions [by my friend]."
Passive voice always involves a to be verb. To be verbs include am, are, been, being, is, was, were. On the other hand, a sentence can include a to be verb without being passive. For example:
"I have been involved in this organization for several years."
"He is leaving in five minutes."
Later we will discuss ways to avoid to be verbs even when they are not in passive-voice constructions.
There are generally two cases when passive voice is acceptable: 1) when there is no defined or tangible subject; 2) when the emphasis really should be on the object of the action. In these cases, the alternative is often awkward and less natural sounding.
CASE 1: He is referred to as "the great one."
AWKWARD ALTERNATIVE: The general public refers to him as "the great one."
CASE 2: For the fifth time this year, Johnson was hit by a pitch.
AWKWARD ALTERNATIVE: For the fifth time this year, a pitch hit Johnson.
As we've already shown, the basic approach to avoiding passive voice is quite simple. Identify the subject of the action (the noun that follows "by" or is otherwise implied) and bring that to the front of the clause. Remove the to be verb. Adjust any other word-order issues as needed. Try these five examples as an exercise:
Active language comes not just from avoiding passive voice but further requires the use of strong action verbs. In addition to avoiding to be verbs, you should try to replace helping verbs such as have, had, has, do, does, did and other vague verbs like got and get.
BEFORE: I had opportunities to develop my skills.
AFTER: I sought opportunities to develop my skills.
BEFORE: I got the promotion through hard work.
AFTER: I earned the promotion through hard work.
BEFORE: She did well in this competitive environment.
AFTER: She thrived in this competitive environment.
BEFORE: My mother didn't want to show up without a gift.
AFTER: My mother hesitated to show up without a gift.
BEFORE: The salesman told the audience about his products.
AFTER: The salesman promoted his products to the audience.
The last two examples demonstrate the lack of clear distinction between strong and weak verbs. There's nothing in the dictionary that will tell you that promoted sounds stronger than told. It's largely a matter of how much meaning the word contains. Promoted has a more precise and nuanced meaning than told.
You can certainly develop a strong eye for these subtle issues, but active writing is an area where professional editing can make a substantial difference.