Presupposition
& Entailment
A presupposition is something the speaker assumes to be the case
prior to making an utterance. Speakers, not sentences, have
presuppositions.
An entailment is something that logically follows from what is
asserted in the utterance. Sentences, not speakers, have
entailments.
Mary's brother bought three horses.
•The speaker will normally be expected to have the presuppositions that a person
called Mary exists and that she has a brother. The speaker may also hold the more
specific presuppositions that Mary has only one brother and that he has a lot of
money. All of these presuppositions are the speaker's and all of them can be
wrong, in fact.
•The sentence will be treated as having the entailments that Mary's brother bought
something, bought three animals, bought two horses, bought one horse, and many
other similar logical consequences. These entailments follow from the sentence,
regardless of whether the speaker's beliefs are right or wrong, in fact
Types of presupposition
•As already illustrated in ex.1, the possessive construction in English is associated with a presupposition
of existence. The existential presupposition is not only assumed to be present in possessive
constructions (for example, 'your car’ presupposes 'you have a car'), but more generally in any definite
noun phrase.
•By using any of the expressions below, the speaker is assumed to be committed to the existence of the
entities named.
the King of Sweden, the cat, the girl next door, the Counting Crows
•The presupposed information following a verb like 'know’ can be treated as a fact and is described as a
factive presupposition. A number of other verbs, such as 'realize' and 'regret’ in , as well as phrases
involving 'be' with 'aware', 'odd', and 'glad’ have factive presuppositions.
a. She didn't realize he was ill. He was ill.
b. We regret telling him. We told him.
c. I wasn't aware that she was married. She was married.
d. It isn't odd that he left early. He left early.
e. I'm glad that it's over. It's over.
•In lexical presupposition, the use of one form with its asserted meaning is conventionally interpreted with
the presupposition that another (non-asserted) meaning is understood.
•Each time you say that someone 'managed' to do something, the asserted meaning is that the person
succeeded in some way. When you say that someone 'didn't manage', the asserted meaning is that the
person did not succeed.
•There is a presupposition (nonasserted) that the person 'tried' to do that something. So, 'managed’ is
conventionally interpreted as asserting 'succeeded’ and presupposing 'tried'. Other examples, involving the
lexical items, 'stop', 'start', and 'again', are presented, with their presuppositions.
• a. He stopped smoking He used to smoke.
b. They started complaining. They weren’t complaining before
• c. You're late again You were late before
• In the case of lexical presupposition, the speaker's use of a particular expression is taken to presuppose
another (unstated) concept, whereas in the case of a factive presupposition, the use of a particular expression
is taken to presuppose the truth of the information that is stated after it.
•There are also structural presuppositions. In this case, certain sentence structures have been analyzed as
conventionally and regularly presupposing that part of the structure is already assumed to be true.
For example, the wh-question construction in English is conventionally interpreted with the presupposition that
the information after the wh-form (i.e. 'When' and 'Where') is already known to be the case.
a. When did he leave? He left
b. Where did you buy the bike? You bought the bike.
•A non-factive presupposition is one that is assumed not to be true. Verbs like
'dream', 'imagine', and 'pretend’ are used with the presupposition that what
follows is not true.
a. I dreamed that I was rich. I was not rich.
b. We imagined we were in Hawaii. We were not in Hawaii.
c. He pretends to be ill. He is not ill.
•This type of structure creates a counterfactual presupposition, meaning that what is
presupposed is not only not true, but is the opposite of what is true, or 'contrary to facts'. A
conditional structure of the type shown, generally called a counterfactual conditional, presupposes
that the information in the if-clause is not true at the time of utterance.
If you were my friend, you would have helped me. You are not my friend.
Entailment
Rover chased three squirrels.
a. Someone chased three squirrels.
b. Rover did something to three squirrels.
c. Rover chased three of something.
d. Something happened.
Constancy under negation
Interestingly, when we produce the opposite of the sentence by negating it, we find that the relationship
of presupposition doesn't change. That is, the same proposition, repeated as , continues to be presupposed by
as shown in:
Mary’s dog is cute. AND Mary’s dog isn’t cute. The presupposition is still the same, i.e., Mary has a dog.
•This property of presupposition is generally described as constancy under negation. Basically, it means that the
presupposition of a statement will remain constant (i.e. still true) even when that statement is negated
