What is voice?
Voice (more technically known as diathesis) is a grammatical feature that describes the relationship between the verb and the subject (also known as the agent) in a sentence. More specifically, voice describes how the verb is expressed or written in relation to the agent.
There are two main types of voice: active voice and passive voice. A third type of voice called “middle” voice also exists but is less commonly used. Here are some examples of the three types of voice:
- “She wrote a novel.” (active voice)
- “The house was purchased by an elderly couple.” (passive voice)
- “The cat licked itself.” (“middle” voice)
A verb is in the active voice when the agent of the verb (the person or thing that performs the action specified by the verb) is also the subject of the sentence. The active voice is the most common type of voice in both spoken and written English, and is generally considered to be the default voice.
Not all active-voice verbs are required to take an object. Any object present, however, must come after the verb (which always comes after the agent). For example:
- “The boy sang a song.” (with an object, a song)
- “I am watching a movie.” (with an object, a movie)
- “Vivian sings well.” (without an object)
A sentence uses the passive voice when the subject is acted upon by the verb. Passive-voice sentences are structurally opposite to active-voice sentences, with the object (now the subject* of the sentence) coming before the verb and the verb coming before the agent of the action. A passive-voice verb is used in the past participle form preceded by the auxiliary verb be, and the preposition by is inserted before the agent to form a prepositional phrase. For example:
- “Angie will perform a famous piano piece tomorrow night.” (active voice)
- “A famous piano piece will be performed by Angie tomorrow night.” (passive voice)
- “Thousands of people have already read his new book.” (active voice)
- “His new book has already been read by thousands of people.” (passive voice)
(*When converting a sentence from active to passive, the original object becomes the new subject due to its position at the beginning of the sentence. At the same time, the agent changes into the object of a prepositional phrase.)
Unlike active-voice, passive-voice sentences do not require agents. If an agent is unknown or irrelevant, you may eliminate the prepositional phrase containing the agent. For example:
- “The light bulb was patented by Thomas Edison in 1880.” (with agent)
- “The light bulb was patented in 1880.” (without agent)
- “The wedding venue has been decided on by the bride and groom.” (with agent)
- “The wedding venue has been decided on.” (without agent)
The term “middle” voice describes a type of voice that is a combination of sorts between the active and passive voices. The middle voice is not clearly defined in the English language; that is, it does not have a verb form specific to it. It does, however, contain several odd or irregular verb usages that are said to correspond most closely with the middle voice of other languages.
In most “middle”-voice sentences, the agent performs the verb’s action on itself. To compensate for the lack of a middle-voice verb form, these verbs are typically followed by a reflexive pronoun. For example:
- “My girlfriend always checks herself in the mirror before we go out.”
- “The dog bit itself on the tail.”
“Middle” voice can also be used to describe some intransitive verbs. These verbs syntactically appear active (agent + verb) but function more similarly to verbs in the passive voice. In other words, the agent is being acted upon (like the passive voice) despite its position in front of the verb (as in the active voice). For example:
- “The lasagna cooked in the oven for several hours.” (The verb cook is acting upon the agent lasagna.)
- “The bicycle broke without warning.” (The verb break is acting upon the agent bicycle.)