A couple months ago, I did a post on the grammatical categories of verb tense and aspect. Now I’d like to continue on with this series and take a look at another category: passive and active voice. Many writers understand very well what the passive voice is, but as I mentioned in my previous grammar post, it can be confused with the progressive and perfect aspects. Seeing as I can’t do anything halfway, this is a post for those who’d like to acquire a deeper understanding of how passive and active sentences are actually formed. In doing so, this may help you understand how you’re using your sentences in your own writing.
So what are passive and active voice?
In short, a passive sentence is a sentence whose subject is not the one doing the action in a normal transitive sentence. What is that, you ask? A transitive sentence is a sentence that has a subject and an object, which affects or is affected by the verb. An intransitive sentence doesn’t have an object.
So, let’s say we have the following parts of speech: a subject (S), a verb (V), an object (O), and a prepositional phrase (PP). The following sentences should be parsed grammatically this way:
Transitive sentence: I read the book.
(1) I read the book.
S V O
Intransitive sentence: I grew up in Alabama.
(2) I grew up in Alabama.
S V PP
In sentence (1), the object is defined by its relationship to the verb. It is clear that the subject “I” is the one who is doing the reading. In sentence (2), there is no object because the act of growing up is reflected upon the subject. The prepositional phrase is additional information and does not affect the act of growing up itself. However, the subject “I” is still the one doing the action.
I’ll note that due to a lack of an object, intransitive sentences can’t be passive, but there are verbs that can be both transitive and intransitive depending on the context.
(3) Transitive: He stood the ladder in the doorway.
(4) Intransitive: He stood in the doorway.
In sentence (3), there is a clear subject (he) who does the action (stood) to a clearly defined object (the ladder). In sentence (4), the verb is reflexive. The subject (he) is more or less performing the action (stood) to itself. An object is unnecessary, but the sentence is still active since the subject (he) is still the grammatical subject of the sentence.
But what does this have to do with passive/active voice?
When a sentence is active, the subject is the agent of the action (meaning the one who is doing the action) — an action which is then expressed by a transitive verb (meaning the verb which will have an object following it). The object that follows the verb is affected by the verb and by the subject who initiates the action.
In a passive sentence, however, the affected object becomes the subject of the sentence, and the agent itself is either expressed with a prepositional phrase or left ambiguously unmarked. The verb form itself consists of the auxiliary verb be plus the past participle (-ed participle).
(5) The horse (OBJ) is (auxiliary) ridden (past participle) every day (ADV).
Using the above information, consider the following structure of the next two example sentences:
If the subject of the sentence is the agent, the sentence is active.
(6) The teacher read the book.
S V O
If the subject of the sentence is the object and the agent comes after the verb, the sentence is passive.
(7) The book was read by the teacher.
S V PP
In sentence (7), the book is the subject of the sentence, but the book itself is not the agent of the action, meaning the book is not the one doing the reading. Here we know who is reading the book, or in other words, we know who/what the agent is (the teacher). However, the agent is expressed as a prepositional phrase, is placed after the verb, and is not the grammatical subject of the sentence, thus making the sentence passive.
As writers, we don’t need to have the linguistic know-how to form active or passive sentences, but it does help to have some idea as to why we’re doing what we’re doing. I’ve read various tricks and tips for testing a sentence to see if it’s passive. One that was mentioned in my critique group was to add ‘by zombies’ (courtesy of Amanda, I believe) after the verb — if it fits, then it’s probably passive. The couch was eaten by zombies. (Unless it’s a sentence like “He was standing by zombies.” Remember: that’s intransitive. NOT PASSIVE! )
If you found this post to be helpful, consider checking out the others in this series: