Presupposition

Presupposition concerns the way in which propositions already presumed in a discourse context are usually not stated or questioned, but encoded in a more ‘background’ way. For example, “Has he stopped bothering you?” presupposes the proposition that you and I know that he has been bothering you, and asks whether this has stopped.
The classical test for presupposition is survival under negation: “He hasn’t stopped bothering me” and “He has stopped bothering me” both presuppose that he was bothering me.
Languages have complex systems for foregrounding and backgrounding information in this way. Thus mental attitude verbs, like know or regret, or change of state verbs like start and stop presuppose their complements, definite descriptions (like the king of Buganda) presuppose the existence of the entities referred to, iteratives like again (as in John did it again) presuppose earlier occurrences, and so on.
The phenomena and corresponding explanations are complex, but the relevance to pragmatics is that presupposition clearly implies that natural languages are built to trade on, and signal, the dependency of utterances on propositions already taken for granted. The pragmatic aspects of the phenomena are often underplayed in semantic accounts of the phenomena. For example consider the sentence Sue cried before she finished her thesis – this would normally presume that she finished thesis, this being a presupposition from the before-clause. But the minimally different sentence Sue died before she finished thesis seems to make no such presumption, because of course we happen to know that the dead do not complete theses. This defeasibility, or cancellation of an inference in the context of contrary assumptions, is a hallmark of pragmatic inference.

A PRESUPPOSITION TRIGGER

Definition

A presupposition trigger is a construction or item that signals the existence of a presupposition in an utterance.

Examples (English)

Both positive and negative forms are presented, showing that the presuppositions are constant under negation:

· Definite descriptions
In John saw/didn't see the man with two heads, the definite description the man with two heads triggers the presupposition "There exists a man with two heads." (The unbelievability of the presupposition is what makes the positive utterance unbelievable and the negative one odd.)
· Factive verbs
In John realized/didn't realize that he was in debt, both realize and didn't realize that trigger the presupposition "John was in debt."
Other factives are:

• (it) be odd that
• be sorry/proud/indifferent/glad/sad that
• know that, and
• regret that.

· Implicative verbs
In John managed/didn't manage to open the door, both managed/didn't manage to trigger the presupposition "tried to," as in "John tried to open the door."
Other implicative verbs are :

• avoided (X-ing), which presupposes "was expected to"
• forgot to, which presupposes "ought to have"
• happened to, which presupposes "didn’t plan/intend to," and
• intended to.

. Change of state verbs
In Kissinger continued/didn’t continue to rule the world, both continued/didn’t continue to trigger the presupposition "had been," as in "Kissinger had been ruling the world."
Other change of state verbs are:

• arrive
• begin
• come
• enter
• go
• leave
• stop, and
• take (X from Y), which presupposes "X was at/in/with Y."

· Expressions of repetition
In Carter returned/didn’t return to power, both returned/didn’t return trigger the presupposition "Carter held power before."
Other such expressions are :

• again
• another time
• anymore
• come back
• repeat, and
• restore.

· Expressions of temporal relations
In while Chomsky was revolutionizing linguistics, the rest of social science was/wasn’t asleep, the clause introduced by while triggers the presupposition "Chomsky was revolutionizing linguistics."
Other such conjunctions triggering presuppositions are:

• after
• as
• before
• during
• since, and
• whenever.

· Cleft sentences
In it was/wasn’t Henry that killed Rosie, the cleft structure triggers the presupposition "someone killed Rosie."
The pseudocleft structure in what John lost was his wallet triggers the presupposition "John lost something."
· Stressed constituents
In John did/didn’t compete in the OLYMPICS, the stressed constituent triggers the presupposition "John did compete somewhere."
· Returned actions
In Adolph called Marianne a Valkyrie, and she complimented him back/in return, too, both back/in return, too trigger the presupposition "to call Marianne a Valkyrie is to compliment her."
· Comparisons
In Carol is/isn’t a better linguist than Barbara, the comparison triggers the presupposition "Barbara is a linguist."
· Counterfactual conditions
In if the notice had only said ‘mine-field’ in English as well as Welsh, we would/would never have lost poor Llewellyn, the form of the condition triggers the presupposition "The notice didn’t say mine-field in English."
· Questions
Questions presenting alternatives tend to trigger a presupposition of the truth of one of the alternatives. The utterance is Newcastle in England or in Australia? triggers the presupposition "Newcastle is either in England or in Australia."
Questions containing interrogative pro-forms tend to trigger a corresponding presupposition containing an indefinite pro-form. The utterance who is the professor of linguistics at MIT? triggers the presupposition "someone is the professor of linguistics at MIT."

Source:
Compiled by Karttunen No date and presented by Levinson 1983: 181–184