Presupposition triggers
A presupposition trigger is a lexical item or linguistic construction which is responsible for the presupposition, and thus "triggers" it.[2] The following is a selection of presuppositional triggers following Stephen C. Levinson's classic textbook on Pragmatics, which in turn draws on a list produced by Lauri Karttunen. As is customary, the presuppositional triggers themselves are italicized, and the symbol » stands for 'presupposes'.[3]
Definite descriptions
Main article: Definite description
Definite descriptions are phrases of the form "the X" where X is a noun phrase. The description is said to be proper when the phrase applies to exactly one object, and conversely, it is said to be improper when either there exist more than one potential referents, as in "the senator from Ohio", or none at all, as in "the king of France". In conventional speech, definite descriptions are implicitly assumed to be proper, hence such phrases trigger the presupposition that the referent is unique and existent.
John saw the man with two heads.
»there exists a man with two heads.
Factive verbs
See also: Epistemology § Truth
In Western epistemology, there is a tradition originating with Plato of defining knowledge as justified true belief. On this definition, for someone to know X, it is required that X be true. A linguistic question thus arises regarding the usage of such phrases: does a person who states "John knows X" implicitly claim the truth of X? Steven Pinker explored this question in a popular science format in a 2007 book on language and cognition, using a widely publicized example from a speech by a U.S. president.[4] A 2003 speech by George W. Bush included the line, "British Intelligence has learned that Saddam Hussein recently sought significant quantities of uranium from Africa."[5] Over the next few years, it became apparent that this intelligence lead was incorrect. But the way the speech was phrased, using a factive verb, implicitly framed the lead as truth rather than hypothesis. There is however a strong alternative view that factivity thesis, the proposition that relational predicates having to do with knowledge, such as knows, learn, remembers, and realized, presuppose the factual truth of their object, is incorrect.[6]
Martha regrets drinking John's home brew.
Presupposition: Martha did in fact drink John's home brew.
Frankenstein was aware that Dracula was there.
Presupposition: Dracula was in fact there.
John realized that he was in debt.
Presupposition: John was in fact in debt.
It was odd how proud he was.
Presupposition: He was in fact proud.
Some further factive predicates: know; be sorry that; be proud that; be indifferent that; be glad that; be sad that.
Implicative verbs
John managed to open the door.
»John tried to open the door.
John forgot to lock the door.
»John ought to have locked, or intended to lock, the door.
Some further implicative predicates: X happened to V»X didn't plan or intend to V; X avoided Ving»X was expected to, or usually did, or ought to V, etc.
Change of state or continuation of state verbs
With these presupposition triggers, the current unfolding situation is considered presupposed information.[7]
John stopped teasing his wife.
»John had been teasing his wife.
Joan began teasing her husband.
»Joan hadn't been teasing her husband.
Some further change of state verbs: start; finish; carry on; cease; take (as in X took Y from Z » Y was at/in/with Z); leave; enter; come; go; arrive; etc.
Iteratives
These types of triggers presuppose the existence of a previous state of affairs.[7]
The flying saucer came again.
»The flying saucer came before.
You can't get gobstoppers anymore.
»You once could get gobstoppers.
Carter returned to power.
»Carter held power before.
Further iteratives: another time; to come back; restore; repeat; for the nth time.
Temporal clauses
The situation explained in a clause that begins with a temporal clause constructor is typically considered backgrounded information.[7]
Before Strawson was even born, Frege noticed presuppositions.
»Strawson was born.
While Chomsky was revolutionizing linguistics, the rest of social science was asleep.
»Chomsky was revolutionizing linguistics.
Since Churchill died, we've lacked a leader.
»Churchill died.
Further temporal clause constructors: after; during; whenever; as (as in As John was getting up, he slipped).