Definition of Presupposition & Entailment
• Certain information which is assumed as
already known for the listeners and will not be
• Much more central to pragmatics in the past
• We discuss them to understand the
relationship between semantics and
Differences of Presupposition & Entailment
The speaker assumes
to be the case prior to
making an utterance.
follows from what is
asserted in utterance.
sentences have it.
speakers, have it.
Naturally logic and
Mary’s brother bought three horses.
• Presuppositions are:
• Mary exists.
• Mary has brothers.
• Mary has only one brother.
• He has a lot of money.
• Entailments are:
• Mary’s brother bought something.
• He bought three animals.
• He bought two horses.
• He bought one horse.
• A relationship between two propositions.
a) Mary’s dog is cute. (=p)
b) Mary has a dog. (=q)
c) p >> q (p presuppose q)
• Constancy under negation:
a) Mary’s dog isn’t cute. (= NOT p)
b) Mary has a dog. (=q)
c) NOT p >> q
Constancy Under Negation : another example
a) Everybody knows that john is gay. (=p)
b) Everybody doesn’t know that john is gay. (= NOT p)
c) John is gay. (=q)
d) p >> q && NOT p>> q
• The speakers disagree about the validity of p
while they both assume the truth of q.
• q is proposed by both p and NOT p.
Types of presupposition
Notice : we consider potential presumptions,
which can only become actual presuppositions in
contexts with speakers.
• Speaker is committed to the existence of the
entities named, not only in possessive
constructions, but in any definite noun phrase.
• The King of France
• The cat
• The girl next door
• Your car
• Certain verbs or construction indicate that
something is a fact.
• know, realize, regret
• be aware, be odd, be glad
• We regret telling him. --> We told him.
• She didn’t realize he was ill. --> He was ill.
• I’m glad it’s over --> It’s over.
• This assumption is that in using one word, the
speaker can act as if another non-asserted
meaning (word) will be understood.
A. Someone managed to do something.
asserted : The person succeeded in some way.
B. Someone didn’t manage to do something.
asserted : The person did not succeed.
Non-asserted in both: The person tried!
• Lexical items ‘start’ , ‘stop’ and ‘again’ have
• He stopped smoking. >> He used to smoke.
• They started complaining. >> They weren’t
• You are late again. >> you were late before.
• Notice : here, the speaker presuppose
another unstated concept. But in factive
presupposition, the speaker presuppose the
truth of stated information.
• Is the assumption associated with the use
of certain words and phrases.
• In certain sentence structure, part of the
structure is already assume to be true.
• Speaker can use such structure to treat
information as presupposed and hence be
accepted as true by listener or lead him to
believe that the information is necessarily
• Good example is wh-question construction
• When did he leave? >> He left.
• Where did you buy the bike? >> You bought
• Subtle way of making information that the
speaker believes appear to be what the
speaker should believe!
• Is one that is assumed not to be true.
• I dreamed that I was rich. >> I was not rich.
• We imagine we were in Hawaii. >> We were
not in Hawaii.
• He pretends to be ill. >> He is not ill.
• Meaning that what is presupposed is not
only not true, but is the opposite of what is
true, or “contrary to facts.”
• Counterfactual conditional:
• If clauses:
If I had enough money, I would buy that house.
>> I do not have enough money
• embedded clause after wish :
They wish they could go on vacation now.
>> They cannot go on vacation now.
Type Example Presupposition
Existential The X >> x exists
Factive I regret leaving >> I left
Non-factive He pretended to
>> he wasn’t
Lexical He managed to
>>He tried to
Structural When did she
>> she died.
Counterfactual If I weren’t ill, >> I am ill
The projection Problem
• The meaning of the whole sentence is a
combination of the meaning of its parts.
• We expect the presupposition of a simple
sentence will continue to be true when that
simple sentence becomes part of a more
complex sentence cause the meaning of the
whole sentence is a combination of the
meaning of its parts.
• It doesn’t happen!
a) George regrets getting Marry pregnant.(=p)
b) George got Marry Pregnant.(=q)
d) He doesn’t get her pregnant.(=r)
e) George regrets getting Marry pregnant, but
he doesn’t get her pregnant.(=p & r)
f) p & r >> NOT q
• When we combine two utterance (types
presupposition), it can’t survive to become the
meaning of some complex sentences. It is known
as projection problem.
• Presupposition don’t ‘project’ is that they are
destroyed by entailments.
• Entailment is something that necessarily follows
from what is asserted. The entailment is simply
more powerful than the presupposition.
• That’s why we call them potential presuppositions.
The projection Problem, cont.
a) Nobody realized that Kelly was ill.(=p)
b) Kelly was ill. (=q)
c) p >> q
d) I imagined that Kelly was ill. (=r)
e) Kelly was not ill. (=NOT q)
f) r >> NOT q
g) I imagined that Kelly was ill and nobody
realized that she was ill.(=r & p)
h) r & p >> NOT q
You have a presupposition q and an
entailment not q
• Not a pragmatic concept, but a purely logical
• Symbolized by II-
• Eg: Rover chased three squirrels. (= p)
a. Something chased three squirrels. (= q)
b. Rover did something to three squirrels. (= r)
c. Rover chased three of something. (= s)
d. Something happened. (= t)
p II- q
1. Background entailment
• Logical concept of entailment
• A very large number of them exists for an
2. Foreground Entailments
• The speaker can communicate, usually by means
of stress, more important for interpreting intended
meaning than any others.
Types of Entailment
• Rover chased THREE squirrels.
• Rover chased a certain number of squirrels.
• ROVER chased three squirrels.
• The focus shift to Rover and the main assumption
is that something chased three squirrels.
• ‘it-cleft’ structure has a similar function:
• It wasn’t ME who took your money.
Marking the Main Assumption