English passive voice
The passive voice is a grammatical construction (specifically, a "voice"). The noun or noun phrase that would be the object of an active sentence (such as Our troops defeated the enemy) appears as the subject of a sentence with passive voice (e.g. The enemy was defeated by our troops).
The subject of a sentence or clause featuring the passive voice typically denotes the recipient of the action (the patient) rather than the performer (the agent). The passive voice in English is formed periphrastically: the usual form uses the auxiliary verb be (or get) together with the past participle of the main verb.
For example, Caesar was stabbed by Brutus uses the passive voice. The subject denotes the person (Caesar) affected by the action of the verb. The agent is expressed here with the phrase by Brutus, but this can be omitted. The equivalent sentence in active voice is Brutus stabbed Caesar, in which the subject denotes the doer, or agent, Brutus. A sentence featuring the passive voice is sometimes called a passive sentence, and a verb phrase in passive voice is sometimes called a passive verb.
English allows a number of passive constructions which are not possible in many of the other languages with similar passive formation. These include promotion of an indirect object to subject (as in Tom was given a bag) and promotion of the complement of a preposition (as in Sue was operated on, leaving a stranded preposition).
Use of the English passive varies with writing style and field. Some publications' style sheets discourage use of the passive voice, while others encourage it. Although some purveyors of usage advice, including George Orwell in Politics and the English Language and William Strunk, Jr. and E. B. White in The Elements of Style, discourage use of the passive in English, its usefulness is generally recognized, particularly in cases where the patient is more important than the agent, but also in some cases where it is desired to emphasize the agent.
- 1 Identifying the English passive
- 2 Reasons for using the passive voice
- 3 Style advice
- 4 Passive constructions
- 5 Middle voice and passival
- 6 See also
- 7 References
- 8 External links
Identifying the English passive
The passive voice is a specific grammatical construction; the essential components, in English, are a form of the auxiliary verb be (or sometimes get) and the past participle of the main verb denoting the action. The agent (the doer of the action) may be specified using a prepositional phrase with the preposition by but this is optional. It can be used, for instance, in declarative, interrogative, and imperative clauses, and in gerundial constructions. For example:
- "Being attacked by Geoffrey Howe was like being savaged by a dead sheep."
- "Have you ever been kicked by an elephant?"
- "Kennedy was assassinated in 1963."
- "Mistakes were made."
- "The window got broken."
- "Don't get killed."
Distinction between passive voice and participial adjective
A distinction is made between the above type of clause and a superficially similar construction where the past participle is used as an adjective, and the verb be or similar is simply a copula linking the subject of the sentence to that adjective. For example:
- I am excited (right now).
is not passive voice, because the participle excited is used as an adjective denoting a state, not to as a verb (as it would in the passive the electron was excited with a laser pulse). See Stative and adjectival uses below.
Misuse of the term
Though the passive can be used for the purpose of concealing the agent, this is not a valid way of identifying the passive, and many other grammatical constructions can be used to accomplish this. Not every expression that serves to take focus away from the performer of an action is an instance of passive voice. For instance "There were mistakes." and "Mistakes occurred." are both in the active voice. Occasionally, authors express recommendations about use of the passive unclearly or misapply the term "passive voice" to include sentences of this type. An example of this incorrect usage can be found in the following extract from an article from The New Yorker about Bernard Madoff (bolding and italics added; bold text indicates the verbs misidentified as passive voice):
Two sentences later, Madoff said, "When I began the Ponzi scheme, I believed it would end shortly, and I would be able to extricate myself, and my clients, from the scheme." As he read this, he betrayed no sense of how absurd it was to use the passive voice in regard to his scheme, as if it were a spell of bad weather that had descended on him . . . In most of the rest of the statement, one not only heard the aggrieved passive voice, but felt the hand of a lawyer: "To the best of my recollection, my fraud began in the early nineteen-nineties."
The intransitive verbs would end and began are in fact in the active voice. Although the speaker may be using words in a manner that diverts responsibility from him, this is not accomplished by use of passive voice.
Reasons for using the passive voice
The passive voice can be used without referring to the agent of an action; it may therefore be used when the agent is unknown or unimportant, or the speaker does not wish to mention the agent.
- Three stores were robbed last night. (the identity of the agent may be unknown)
- A new cancer drug has been discovered. (the identity of the agent may be unimportant in the context)
- Mistakes have been made on this project. (the speaker may not wish to identify the agent)
The last sentence illustrates a frequently criticized use of the passive – the evasion of responsibility by failure to mention the agent (which may even be the speaker himself).
Agentless passives are common in scientific writing, where the agent may be irrelevant:
- The mixture was heated to 300 °C.
However the passive voice can also be used together with a mention of the agent, using a by-phrase. In this case the reason for use of the passive is often connected with the positioning of this phrase at the end of the clause (unlike in the active voice, where the agent, as subject, normally precedes the verb). Here, in contrast to the examples above, passive constructions may in fact serve to place emphasis on the agent, since it is natural for information being emphasized to come at the end:
- Don't you see? The patient was murdered by his own doctor!
In more technical terms, such uses can be expected in sentences where the agent is the focus (comment, rheme), while the patient (the undergoer of the action) is the topic or theme (see Topic–comment). There is a tendency for sentences to be formulated so as to place the focus at the end, and this can motivate the choice of active or passive voice:
- My taxi hit an old lady. (the taxi is the topic, the lady is the focus)
- My mother was hit by a taxi. (the mother is the topic, the taxi is the focus)
Similarly, the passive may be used because the noun phrase denoting the agent is a long one (containing many modifiers), since it is convenient to place such phrases at the end of a clause:
- The breakthrough was achieved by Burlingame and Evans, two researchers in the university's genetic engineering lab.
In some situations, the passive may be used so that the most dramatic word, or punchline, appears at the end of the sentence.
Advice against the passive voice
Many language critics and language-usage manuals discourage use of the passive voice. This advice is not usually found in older guides, emerging only in the first half of the twentieth century. In 1916, the British writer Arthur Quiller-Couch criticized this grammatical voice:
Generally, use transitive verbs, that strike their object; and use them in the active voice, eschewing the stationary passive, with its little auxiliary its’s and was’s, and its participles getting into the light of your adjectives, which should be few. For, as a rough law, by his use of the straight verb and by his economy of adjectives you can tell a man’s style, if it be masculine or neuter, writing or 'composition'.
The active voice is usually more direct and vigorous than the passive . . . This rule does not, of course, mean that the writer should entirely discard the passive voice, which is frequently convenient and sometimes necessary . . . The need to make a particular word the subject of the sentence will often . . . determine which voice is to be used. The habitual use of the active voice, however, makes for forcible writing. This is true not only in narrative concerned principally with action, but in writing of any kind. Many a tame sentence of description or exposition can be made lively and emphatic by substituting a transitive in the active voice for some such perfunctory expression as there is or could be heard.
In 1926, in the authoritative A Dictionary of Modern English Usage, Henry Watson Fowler recommended against transforming active voice forms into passive voice forms, because doing so "...sometimes leads to bad grammar, false idiom, or clumsiness."
In 1946, in the essay Politics and the English Language, George Orwell recommended the active voice as an elementary principle of composition: "Never use the passive where you can use the active."
The Columbia Guide to Standard American English states that:
Active voice makes subjects do something (to something); passive voice permits subjects to have something done to them (by someone or something). Some argue that active voice is more muscular, direct, and succinct, passive voice flabbier, more indirect, and wordier. If you want your words to seem impersonal, indirect, and noncommittal, passive is the choice, but otherwise, active voice is almost invariably likely to prove more effective.
The principal criticism against the passive voice is its potential for evasion of responsibility. This is because a passive clause may be used to omit the agent even where it is important:
- We had hoped to report on this problem, but the data were inadvertently deleted from our files.
Krista Ratcliffe, a professor at Marquette University, notes the use of passives as an example of the role of grammar as "...a link between words and magical conjuring [...]: passive voice mystifies accountability by erasing who or what performs an action [...]."
Advice in favor of the passive voice
Jan Freeman, a columnist for The Boston Globe, said that the passive voice does have its uses, and that "all good writers use the passive voice." For example, despite Orwell's advice to avoid the passive, his Politics and the English Language employs passive voice for about 20 percent of its constructions. By comparison, a statistical study found about 13 percent passive constructions in newspapers and magazines.
Passive writing is not necessarily slack and indirect. Many famously vigorous passages use the passive voice, as in these examples with the passive verbs italicized:
- We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. (United States Declaration of Independence)
- Every valley shall be exalted, and every mountain and hill shall be made low; and the crooked shall be made straight, and the rough places plain. (King James Bible, Isaiah 40:4)
- Now is the winter of our discontent / Made glorious summer by this sun of York. (Shakespeare's Richard III, I.1, ll. 1–2)
- For of those to whom much is given, much is required. (John F. Kennedy's quotation of Luke 12:48 in his address to the Massachusetts legislature, 9 January 1961.)
- Never in the field of human conflict was so much owed by so many to so few. (Winston Churchill addressing the House of Commons, 20 August 1940.)
Merriam–Webster's Dictionary of English Usage recommends the passive voice when identifying the object (receiver) of the action is more important than the subject (agent), and when the agent is unknown, unimportant, or not worth mentioning:
- The child was struck by the car.
- The store was robbed last night.
- Plows should not be kept in the garage.
- Kennedy was elected president.
Despite criticism that the passive can be used to hide responsibility by omitting the agent, the passive can also be used to emphasize the agent. Writers have preferred placing the agent at the end of a clause or sentence to give it greater emphasis, as in the examples given in the previous section:
- Don't you see? The patient was murdered by his own doctor!
- The breakthrough was achieved by Burlingame and Evans, two researchers in the university's genetic engineering lab.
In the most commonly considered type of passive clause, a form of the verb be (or sometimes get) is used as an auxiliary together with the past participle of a transitive verb; that verb is missing its direct object, and the patient of the action (that which would be denoted by the direct object of the verb in an active clause) is denoted instead by the subject of the clause. For example, the active clause:
- John threw the ball.
contains threw as a transitive verb with John as its subject and the ball as its direct object. If we recast the verb in the passive voice (was thrown), then the ball becomes the subject (it is "promoted" to the subject position) and John disappears:
- The ball was thrown.
The original subject (the agent) can optionally be re-inserted using the preposition by.
- The ball was thrown by John.
The above example uses the verb be (in the past tense form was) to make the passive. It is often possible to use the verb get as an alternative (possibly with slightly different meaning); for example, the active sentence "The ball hit Bob" may be recast in either of the following forms:
- Bob was hit by the ball.
- Bob got hit by the ball.
The auxiliary verb of the passive voice (be or get) may appear in any combination of tense, aspect and mood, and can also appear in non-finite form (infinitive, participle or gerund). See the article on English verb forms for more information. Notice that this includes use of the verb be in progressive aspect, which does not normally occur when be is used as a simple copula. Some examples:
- The food is being served. (present progressive passive)
- The stadium will have been built by next January. (future perfect passive)
- I would have got/gotten injured if I had stayed in my place. (conditional perfect passive with get)
- It isn't nice to be insulted. (passive infinitive)
- Having been humiliated, he left the stage. (passive present participle, perfect aspect)
Promotion of indirect objects
Unlike some other languages, English also allows passive clauses in which an indirect object, rather than a direct object, is promoted to the subject. For example:
- John gave Mary a book. → Mary was given a book (by John).
In the active form, gave is the verb; John is its subject, Mary its indirect object, and a book its direct object. In the passive forms, the indirect object has been promoted and the direct object has been left in place. (In this respect, English resembles dechticaetiative languages.)
It is normally only the first-appearing object that can be promoted; promotion of the indirect object takes place from a construction in which it precedes the direct object (i.e. where there is no to or for before the indirect object), whereas promotion of the direct object in such cases takes place from a construction in which the indirect object follows the direct object (this time being accompanied by to or for; see English grammar: Verb phrases). For example:
- John gave Mary a book. → Mary was given a book. (and not normally: ??A book was given Mary.)
- John gave a book to Mary. → A book was given to Mary. (and not: *Mary was given a book to.)
Similar restrictions apply to the prepositional passive, as noted in the following section.
It is also possible, in some cases, to promote the object of a preposition. This may be called the prepositional passive, or sometimes the pseudo-passive (although the latter term can also have other meanings, such as being equivalent to the impersonal passive voice, particularly in descriptions of other languages).
- They talked about the problem. → The problem was talked about.
In the passive form here, the preposition is "stranded"; that is, it is not followed by an object.
The prepositional passive is common especially in informal English. However some potential uses appear grammatically unacceptable; compare the following examples given by Pullum:
- Someone has slept in this bunk. → This bunk has been slept in. (fully acceptable)
- Someone has slept above this bunk. → ??This bunk has been slept above. (barely acceptable)
The second sentence appears unacceptable because sleeping above a bunk does not change its state; the verb phrase been slept above does not express a "relevantly important property" of the bunk.
It is not usually possible to promote a prepositional object if the verb also has a direct object; any passive rendering of the sentence must instead promote the direct object. For example:
- Someone has put a child in this bunk. → *This bunk has been put a child in. (unacceptable)
- Someone has put a child in this bunk. → A child has been put in this bunk. (acceptable)
Exceptions occur with certain idiomatic combinations of verb+object+preposition, such as take advantage of:
- I feel people have taken advantage of me. → I feel I have been taken advantage of. (acceptable)
Stative and adjectival uses
A type of clause that is similar or identical in form to the passive clauses described above has the past participle used to denote not an action, but a state being the result of an action. For example, the sentence The window was broken may have two different meanings:
- The window was broken, i.e. Someone or something broke the window. (action, event)
- The window was broken, i.e. The window was not intact. (resultant state)
The first sentence is an example of the canonical English passive as described above. However the second case is distinct; such sentences are not passive voice, because the participle is being used adjectivally; Such constructs are sometimes called "false passives" or stative (or static, or resultative) passives, since they represent a state or result. By contrast the canonical passives, representing an action or event, may then be called dynamic or eventive passives.
The ambiguity in such sentences arises because the verb be is used in English both as the passive auxiliary and as the ordinary copular verb for linking to predicate adjectives. When get is used to form the passive, there is no ambiguity: The window got broken cannot have a stative meaning. (For ways in which some other languages make this distinction, see Passive voice: Stative and dynamic passive.) If a distinct adjective exists for the purpose of expressing the state, then the past participle is less likely to be used for that purpose; this is the case with the verb open, for which there exists an adjective open, so the sentence The door was opened more likely refers to the action rather than the state, since in the stative case one could simply say The door was open.
Past participles of transitive verbs can also be used as adjectives (as in a broken doll), and the participles used in the above-mentioned "stative" constructions are often considered to be adjectival (in predicative use). Such constructions may then also be called adjectival passives (although they are not normally considered true passives). For example:
- She was relieved to find her car.
Here, relieved is an ordinary adjective, though it derives from the past participle of relieve. In other sentences that same participle may be used to form the true (dynamic) passive: He was relieved of duty.
When the verb being put into the passive voice is a stative verb anyway, the distinctions between uses of the past participle become less clear, since the canonical passive already has a stative meaning. (For example: People know his identity → His identity is known.) However it is sometimes possible to impart a dynamic meaning using get as the auxiliary, as in get known with the meaning "become known".
Passive constructions without an exactly corresponding active
Some passive constructions are not derived exactly from a corresponding active construction in the ways described above. This is particularly the case with sentences containing content clauses (usually that-clauses). Given a sentence in which the role of direct object is played by such a clause, for example
- They say (that) he cheats.
it is possible to convert this to a passive by promoting the content clause to subject; in this case, however, the clause typically does not change its position in the sentence, and an expletive it takes the normal subject position:
- It is said that he cheats.
Another way of forming passives in such cases involves promoting the subject of the content clause to the subject of the main clause, and converting the content clause into a non-finite clause with the to-infinitive. This infinitive is marked for grammatical aspect to correspond to the aspect (or past tense) expressed in the content clause. For example:
- They say that he cheats. → He is said to cheat.
- They think that I am dying. → I am thought to be dying.
- They report that she came back / has come back. → She is reported to have come back.
- They say that she will resign. → e.g. She is said to be going to resign.
Some verbs are used almost exclusively in the passive voice. This is the case with rumor, for example. The following passive sentences are possible:
- He was rumored to be a war veteran. / It was rumored that he was a war veteran.
but it is not possible to use the active counterpart *They rumored that he was a war veteran. (This was once possible, but has fallen out of use.)
Another situation in which the passive uses a different construction than the active involves the verb make, meaning "compel". When this verb is used in the active voice it takes the bare infinitive (without the particle to), but in the passive voice it takes the to-infinitive. For example:
- They made Jane attend classes.
- Jane was made to attend classes.
The construction called double passive can arise when one verb appears in the to-infinitive as the complement of another verb.
If the first verb takes a direct object ahead of the infinitive complement (this applies to raising-to-object verbs, where the expected subject of the second verb is raised to the position of object of the first verb), then the passive voice may be used independently for either or both of the verbs:
- We expect you to complete the project. (you is raised from subject of complete to object of expect)
- You are expected to complete the project. (passive voice used for expect)
- We expect the project to be completed. (passive voice used for complete; now the project is raised to object)
- The project is expected to be completed. (double passive)
Other verbs which can behave similarly to expect in such constructions include order, tell, persuade, etc., leading to such double passives as The man was ordered to be shot and I was persuaded to be ordained.
Similar constructions sometimes occur, however, when the first verb is raising-to-subject rather than raising-to-object – that is, when there is no object before the infinitive complement. For example, with attempt, the active voice construction is simply We attempted to complete the project. A double passive formed from that sentence would be:
- The project was attempted to be completed.
with both verbs changed simultaneously to the passive voice, even though the first verb takes no object – it is not possible to say *We attempted the project to be completed, which is the sentence from which the double passive would appear to derive.
This latter double passive construction is criticized as questionable both grammatically and stylistically. Fowler calls it "clumsy and incorrect", suggesting that it springs from false analogy with the former (acceptable) type of double passive, though conceding its usefulness in some legal and quasi-legal language. Other verbs mentioned (besides attempt) with which the construction is found include begin, desire, hope, propose, seek and threaten. Similarly, The American Heritage Book of English Usage declares this construction unacceptable. It nonetheless occurs in practice in a variety of contexts.
Additional passive constructions
Certain other constructions are sometimes classed as passives. The following types are mentioned by Pullum.
A bare passive clause is similar to a typical passive clause, but without the passive auxiliary verb (so it is a non-finite clause consisting of a subject together with a verb phrase based on a past participle with the passive construction). These can be used in such contexts as newspaper headlines:
- City hall damaged by hail
- Our work done, we made our way back home.
- That said, there are also other considerations.
Other constructions are mentioned in which a passive past participle clause is used, even though it is not introduced by the auxiliary be or get (or is introduced by get with a direct object):
- I had my car cleaned by a professional.
- Jane had her car stolen last week.
- You ought to get that lump looked at.
- This software comes pre-installed by the manufacturer.
In the concealed passive, the present participle or gerund form (-ing form) appears rather than the past participle. This can appear after need, and for some speakers after want (with similar meaning). For example:
- Your car needs washing. (meaning "needs to be washed")
- That rash needs looking at by a specialist.
- His hair wants cutting.
(An idiomatic expression with the same construction is ... doesn't bear thinking about.) The verbs need and want also have similar uses with an object:
- I need/want my room painting.
Middle voice and passival 
The term middle voice is sometimes used to refer to verbs used without a passive construction, but in a meaning where the grammatical subject is understood as undergoing the action. The meaning may be reflexive:
- Fred shaved, i.e. Fred shaved himself
but is not always:
- These cakes sell well, i.e. [we] sell these cakes [successfully]
- The clothes are soaking, i.e. [the water] is soaking the clothes
Such verbs may also be called passival.
Another construction sometimes referred to as passival involves a wider class of verbs, and was used in English until the nineteenth century. Sentences having this construction feature progressive aspect and resemble the active voice, but with meaning like the passive. Examples of this would be:
- The house is building (modern English: The house is being built)
- The meal is eating, (modern English: The meal is being eaten)
A rare example of the passival form being used in modern English is with the following phrase:
- The drums are beating, i.e. the drums are being beaten
This passival construction was displaced during the late 18th and early 19th century by the progressive passive (the form is being built as given above). The grammaticality of the progressive passive, called by some the "imperfect passive," was controversial among grammarians in the 19th century, but is accepted without question today. It has been suggested that the passive progressive appeared just to the east of Bristol and was popularized by the Romantic poets.
- Ergative verb
- Existential clause
- List of common English usage misconceptions
- Mediopassive voice
- Reflexive verb
- Peters, Pam (2004). The Cambridge Guide to English Usage. Cambridge University Press. p. 411. ISBN 0-521-62181-X.
- Wanner, Anja (31 July 2009). Deconstructing the English Passive. Walter de Gruyter. p. 66. ISBN 978-3-11-019632-0. Retrieved 11 November 2012.
- Nature Publishing Group (2010). "How to write a paper". Authors & referees: Writing for a Nature. Retrieved 2010-08-05.
- International Studies Review (10 March 2010). "Journal house style points" (PDF). Retrieved 2010-08-05.
- Merriam-Webster's Dictionary of English Usage. Merriam-Webster. 1994. pp. 720–721. ISBN 978-0-87779-132-4. Retrieved 27 January 2013.
- Gee, James Paul (1974). "Get Passive": On Some Constructions with "get". Indiana University Linguistics Club.
- Huddleston, Rodney; Pullum, Geoffrey (2002). The Cambridge Grammar of the English Language. Cambridge; New York: Cambridge University Press. pp. 1427–1447. ISBN 0-521-43146-8.
- Mark Liberman, "'Passive Voice' — 1397-2009 — R.I.P.," in Language Log, 2009 March 12.
- Nancy Franklin, "The Dolor of Money," The New Yorker, 2009 March 23, at 24, 25.
- Mark Liberman, "The aggrieved passive voice," in Language Log, 2009 March 16.
- The American Heritage Book of English Usage (1996).
- Geoffrey K. Pullum. "The passive in English". Language Log.
- Zwicky, Arnold (2006-07-22). "How long have we been avoiding the passive, and why?". Language Log.
- Arthur Quiller-Couch, On the Art of Writing ch. 7 (1916).
- William Strunk, Jr., The Elements of Style ch. 3, sec. 11 (1918).
- Bell, Griffin B. (1966). "Style in judicial writing". 15 J. Pub. L. 214. Retrieved 2010-03-02.
Fowler, the recognized modern authority on the use of the English language
- Fowler, W. W.; Crystal, David (2009) . A Dictionary of Modern English Usage: The Classic First Edition. Oxford World's Classics Hardbacks Series (reissue ed.). Oxford: Oxford University Press. p. 425. ISBN 978-0-19-953534-7. Retrieved 2010-03-02.
PASSIVE DISTURBANCES. [...] The conversion of an active-verb sentence into a passive-verb one of the same meaning - e.g. of You killed him into He was killed by you - is a familiar process. But it sometimes leads to bad grammar, false idiom, or clumsiness.
- Wilson, Kenneth G. (1992). "The Columbia Guide to Standard American English". Archived from the original on November 19, 2008.
- Ratcliffe, Krista (1996). Anglo-American feminist challenges to the rhetorical traditions: Virginia Woolf, Mary Daly, Adrienne Rich. SIU Press. p. 94. ISBN 978-0-8093-1934-3. Retrieved 2010-10-14.
- Freeman, Jan (2009-03-22). "Active resistance: What we get wrong about the passive voice". The Boston Globe. Boston. ISSN 0743-1791. Retrieved 2010-03-01.
All good writers use the passive voice.
- Address to Massachusetts legislature (Jan. 9, 1961)
- In US English, the general past participle of get is gotten. In British English it is got.
- Dixon, R. M. W. & Alexandra Aikhenvald (1997). "A Typology of Argument-Determined Constructions. pp 72 of Bybee, Joan, John Haiman, & Sandra A. Thompson (eds.)(1997). Essays on Language Function and Language Type: Dedicated to T. Givón. Amsterdam: John Benjamins.
- Language Log: How to defend yourself from bad advice about writing
- Knabe, Norman (January 2009). The Get-Passives as an Emotive Language Device. GRIN Verlag. ISBN 978-3-640-25174-2. Retrieved 13 November 2012.
- H.W. Fowler, A Dictionary of Modern English Usage, Second Revised Edition, 1965. Entry for double passives.
- The American Heritage Book of English Usage, ch. 1, sect. 24 "double passive." Boston: Houghton Mifflin, 1996. http://www.webcitation.org/5QdHYrkv6. Accessed 13 November 2006.
- Neal Whitman, Double Your Passive, Double Your Fun, in Literal Minded. http://literalminded.wordpress.com/2005/05/16/double-your-passive-double-your-fun/. Accessed 13 November 2006.
- Oxford English Dictionary, entry for passival.
- Liberman, Mark (January 13, 2011). "A peeve for the ages". Language Log.
- Vuolo, Mike (May 29, 2012). "The House is Building"? Why you never learned the passival tense, even though it used to be proper English grammar". Slate.
- Merriam-Webster's Dictionary of English Usage. Merriam-Webster. 1994. p. 775. ISBN 978-0-87779-132-4. Retrieved 27 January 2013.