A dummy pronoun is a deictic pronoun that fulfills a syntactical requirement without providing a contextually explicit meaning of its referent. As such, it is an example of exophora.
Dummy pronouns are used in many Germanic languages, including German and English. Pronoun-dropping languages such as Spanish, Portuguese, Chinese, and Turkish do not require dummy pronouns.
A dummy pronoun is used when a particular verb argument (or preposition) is nonexistent (it could also be unknown, irrelevant, already understood, or otherwise "not to be spoken of directly") but when a reference to the argument (a pronoun) is nevertheless syntactically required. For example, in the phrase "It is obvious that the violence will continue", it is a dummy pronoun, not referring to any agent. Unlike a regular pronoun of English, it cannot be replaced by any noun phrase.
The term dummy pronoun refers to the function of a word in a particular sentence, not a property of individual words. For example, it in the example from the previous paragraph is a dummy pronoun, but it in the sentence "I bought a sandwich and ate it" is a referential pronoun (referring to the sandwich).
In the phrase "it is raining—", the verb to rain is usually considered semantically impersonal, even though it appears as syntactically intransitive; in this view, the required it is to be considered a dummy word.
However, there have been a few objections to this interpretation. Noam Chomsky has argued that the it employed as the subject of English weather verbs can control the subject of an adjunct clause, just like a "normal" subject. For example, compare:
If this analysis is accepted, then the "weather it" is to be considered a "quasi-(verb) argument" and not a dummy word.
Some linguists such as D. L. Bolinger go even further, claiming that the "weather it" simply refers to a general state of affairs in the context of the utterance. In this case, it would not be a dummy word at all. Possible evidence for this claim includes exchanges such as:
where it is implied to mean "the local weather".
Other examples of semantically empty it are found with raising verbs in "unraised" counterparts. For example:
Dummy it can also be found in extraposition constructions in English, such as the following:
In English, dummy object pronouns tend to serve an ad hoc function, applying with less regularity than dummy subjects. Dummy objects are sometimes used to transform transitive verbs to a transitive light verb form: e.g., do → do it, "to engage in sexual intercourse"; make → make it, "to achieve success"; get → get it, "to comprehend". Prepositional objects are similar: e.g., with it, "up to date"; out of it, "dazed" or "not thinking". All of these phrases, of course, can also be taken literally. For instance:
It has been proposed[by whom?] that elements like expletive there in existential sentences and pro-forms in inverse copular sentences play the role of dummy predicate rather than dummy subject, so that the postverbal noun phrase would rather be the embedded subject of the sentence.