In English, sentences can have one of two kinds of voice, active or passive, depending on how the subject relates to the verb. That is, a subject can do something or have something done to it. If the subject does something, it is the agent of an action, and the sentence is in the active voice. If the subject has something done to it, it is the goal of an action, and the sentence is in the passive voice. The following diagram illustrates the pattern for passive voice.

	Identifying Passive Constructions
	Uses and Abuses of Passive Voice
	Some Pointers
	Start the Style Exercise for the Passive Voice

Identifying Passive Construction

AGENT ACTION GOAL ACTIVE VOICE: Some engineers design bridges. PASSIVE VOICE: Bridges are designed by some engineers.   GOAL ACTION AGENT Note that in a passive construction, the verb phrase contains the verb to be followed by the active verb in its past participle form (usually the verb root with an -ed ending), and then the phrase usually ends with the preposition by: is calculated by, was measured by, were delivered by, will be completed by, has been finished by. As you have likely noticed, the past participle (the passive form of the active verb) generally looks like the past tense form of the verb. (V-ed). For some verbs, the past participle has its own form. For example, the past participle of to write is written, of to speak is spoken, and of to begin is begun. If you are confused by grammatical terms, you may recognized the patterns more easily by studying examples: Active Voice Passive Voice The boss spoke to her about being late. She was spoken to by the boss about being late. Or She was spoken to about being late. I delayed the project. The project was delayed by me. Or The project was delayed. They finally completed the job. The job was finally completed by them. Or The job was finally completed. The agency has provided the terms of reference for this study. The terms of reference for this study have been provided by the agency. Note that agents can be deleted in some passive sentences, as indicated by the alternative passive forms for the first three sentences. Top | Next

Uses and Abuses of Passive Voice

Passive constructions serve a number of useful purposes. First, you can change the emphasis of a sentence by moving the goal to the subject of the sentence. For example, if the topic of a paragraph is a bridge rather than the engineers who built it, you can make the bridge the subject of the sentence by intentionally using a passive construction: The Golden Gate bridge was designed to combine form and function to dramatic effect. Because agents can be omitted, passive constructions are particularly useful when the agent is unknown (The program was written in C++) or when the agent is obvious or unnecessary (The project was finally completed last night). Because the agent can be omitted, the passive voice also allows you to avoid appearing to blame someone. That is, you can say that a device was damaged without mentioning who damaged it. But you can also use passive constructions to avoid responsibility. That is, you can say that a decision was made without admitting that you made the decision. Unfortunately, if you omit agents without thinking, your readers may assume that you are avoiding responsibility when that is not your intention. One of the reasons passive sentences are so common in technical and scientific writing is that they allow you to communicate an impression of objectivity. After the experiment was completed, the data was analyzed sounds more objective than After I completed the experiment, I analyzed the data. The notion that scientific objectivity should be reflected in scientific writing may well explain why some writers avoid using active voice and first-person pronouns. You might also want to question the value of this objectivity in some situations. For example, compare the procedure was changed (a passive construction) with we changed the procedure (its active counterpart). The procedure did not change spontaneously; someone changed the procedure. Who did it may be useful information. Omitting the agent may leave readers wondering who made the change, distracting their attention by raising a question and thus disrupting the flow of information. Another reason to pay attention to passive constructions is that they can be less clear than active ones. In fact, many writers unconsciously shift to passive sentences when they are unsure of what they are saying or are struggling to express their thoughts. In some cases, if you take a passive sentence and rewrite it as an active one, you will realize that the passive sentence did not express your ideas correctly. If the active sentence is more clear for you as the writer, it will certainly be more clear for readers. Top | Previous | Next

Some Pointers

Some common uses and abuses of the passive voice are summarized in the table below. Uses of Passive Voice Abuses of Passive Voice Changing the emphasis of a sentence Omitting unknown or unnecessary agents Avoiding blaming someone Communicating objectivity Using habitually Obscuring meaning Avoiding responsibility Creating a false sense of objectivity Top | Previous

	Exercise

When revising your own writing, consider the context for the sentence and whether an active or passive sentence is most appropriate to achieve effective order and emphasis. Hint 1. Original: An explanation of atmospheric stability and a detailed evaluation of its application to this air quality evaluation is contained in Appendix A. 1. Hinted: An explanation of atmospheric stability and a detailed evaluation of its application to this air quality evaluation is contained in Appendix A. 1. Revised: Hint 2. Original: The terms of reference for this study have been provided by the agency. 2. Hinted: The terms of reference for this study have been provided by the agency. 2. Revised: Explanation For the last example, the passive sentence is appropriate only if the phrase terms of reference is the subject and the agency is the new information. When the agent is named in a passive sentence (by the agency), revision is relatively simple: you reverse the beginning and ending of the sentence and use the active form of the verb. Revision is not quite so straightforward when the agent is missing: Hint 3. Original: Therefore, the regional wind speed and direction patterns are considered in this air quality evaluation. 3. Hinted: Therefore, the regional wind speed and direction patterns are considered in this air quality evaluation. 3. Revised: Hint 4. Original: Kirchhoff’s Voltage Law was confirmed by directly measuring the voltages in the circuit. 4. Hinted: Kirchhoff’s Voltage Law was confirmed by directly measuring the voltages in the circuit. 4. Revised: Explanation When the agent is omitted from a passive sentence, you can substitute another noun (This evaluation) or add the missing agent (We). One useful strategy is to add a dummy agent (someone, something) and then determine the appropriate agent or substitute subject. Turning passive sentences into active ones sometimes requires other revision strategies. Hint 5. Original: As part of the analysis of roadway improvements, the review of signal progression along Cambie Street will be required. 5. Hinted: As part of the analysis of roadway improvements, the review of signal progression along Cambie Street will be required. 5. Revised: Explanation Making sense of the original sentence requires reading it in context. In context, as part of is unnecessary, so we can eliminate it and use a verbal phrase (Analyzing roadway improvements) as the subject of the sentence. Note that the active revision is both clearer and shorter. If you use the passive voice without a good reason, you add unnecessary words and make your sentences less clear than if you  used the active voice. Examine a recent piece of your writing -- or run it through a grammar checker. Is the passive voice the default for your style? If so, you should learn to recognize passive constructions and revise to make your writing more active. But do not forget that passives can be useful and cannot always be eliminated. Instead they should be used for a purpose: to create an appropriate emphasis, when the goal of an action is the desired subject, or when the agent is unknown.