Presupposition (types of presuppositions) and entailment

two technical terms used to describe two different aspects of the information

about which speakers assume that it is already known by their listeners and

which is consequently counted as part of what is communicated but not said


presupposition

‑ something that the speaker assumes to be the case prior to making an utterance

‑ speakers (not sentences) have presuppositions

entailment

‑ something that logically follows from what is asserted in the utterance

‑ sentences (not speakers) have entailments


1. Mary’s brother bought three horses.

2 a. Mary’s dog is clever. (=p)

   b. Mary has a dog. (=q)

   c. p >> q

The same presupposition continues to be presupposed by NOTp.

Note: the symbol >> means ‘presupposes’

3 a. Mary’s dog is not clever. (NOTp)

   b. Mary has a dog. (=q)

   c. NOT p >> q


This property of presupposition is described as constancy under negation.

4 a. Everybody knows that John is happy. (=p)

   b. Everybody doesn’t know that John is happy. (=NOTp)

   c. John is happy. (=q)

   d. p >> q & NOT p >> q

The same presupposition is presupposed both by p and NOTp.


Types of presupposition ‑ potential presuppositions:

Presuppositions are associated with the use of a large number of words, phrases, and structures.
These forms are considered as indicators of potential presuppositions, which can only become actual
presuppositions in contexts with speakers.


There are several types of potential presuppositions:

Type

              Example

                                       Presupposition

Existential

              The X

                                       >> X exists.

Factive

              I regret leaving.

                                       >> I left.

Lexical

              He managed to escape.

                                       >> He tried to escape.

Structural

              When did she die?

                                       >> She died.

Non-factive

              He pretended to be happy.

                                       >> He wasn’t happy.

Counterfactual

              If I weren’t ill, …..

                                       >> I am ill.


Some other examples:

5. the girl next door, the king of Sweden

6 a. She didn’t realize he was ill.

    b. I am glad that it's over.

    c. I regret telling him.

7 a. He stopped smoking.

    b. You’re late again.

    c. They started complaining.

8 a. Where did you buy the bike?

    b. Where did he leave?

    c. How fast was the car going when it ran the red light?

9 a. I dreamed that I was rich.

   b. He pretends to be ill.

10. If you were my friend, you would have helped me.


Presupposition and entailment

11 a. The King of England visited us.

    b. The King of England doesn’t exist!


The power of entailment can also be used to cancel presuppositions.

The entailment (e.g. there is not a King of England) is more powerful than the presupposition (e.g.
the existential presupposition there is a King of England).

When a person (e.g. in 11a above) uses a definite description of the type ‘the X’, he or she
normally presupposes the existence of the entity described, but this presupposition can be
cancelled by the entailment (e.g. in 11b above).


Conclusion:

The best thing is to think of all the types of presuppositions as ‘potential presuppositions’ which
only become actual presuppositions when intended by speakers to be recognized as such within
utterances. Speakers can indicate that

the potential presupposition is not being presented as a strong assumption, as in:

12 a. What’s that guy doing in the parking lot?

     b. He’s looking for his car or something.

Note: It is never the word or phrase that has a presupposition. Only speakers

can have presuppositions.


Ordered entailments

background entailments x foreground entailment

13. Rover chased three squirrels.

14 a. Something chased three squirrels.

    b. Rover did something to three squirrels.

    c. Rover chased three of something.

    d. Something happened.


The speaker communicates, typically by stress, which entailment is assumed

to be in the foreground, or more important for interpreting intended meaning.


15 a. Rover chased THREE squirrels.

     b. ROVER chased three squirrels.


A similar function (to that of stress as used in 15ab) is exhibited by it‑cleft construction in
English.


16. It was ROVER that chased the squirrels.

17. It wasn’t ME who took your money.


In Examples 16 and 17, the speaker can communicate what he/she believes the hearer may already be
thinking (i.e. the foreground entailment). 17 can be used to attribute the foreground entailment to
the hearer without actually stating it (e.g. as a possible accusation). Examples 16, 17 illustrate
how more is being communicated than said.