What We ll Do Observe what Presuppositions are. Presuppositions: - PDF document

What We ’ ll Do • Observe what Presuppositions are. Presuppositions: The • Study their effect on communication. Projection Problem • Examine their similarity to pronouns. • Examine their differences from Human Communication 1 pronouns. Lecture 21 • We ’ ll extend the grammar to deal with them. • We ’ ll produce a better account of the Assumptions Hidden in Assumptions Hidden in Language (a) Language (b) (1) Jo ’ s wife just had a baby. • Information that ’ s conveyed this way is • You could argue that (1) carries no meaning called a presupposition. at all unless Jo has a wife (to convince • The words that trigger them are called yourself of this, negate the sentence and see presupposition triggers . what happens). • So I ’ m not asserting that Jo has a wife • Rather, I ’ m assuming: – she exists, – the hearer is happy with this assumption and I ’ m opening discussion on her having a baby. 1

Weird Things Presuppositions Weird Things Presuppositions Do (a) Do (b) • Presuppositions can project from c. If you don ’ t like logic, then the course embeddings. on pragmatics is really challenging. – If the trigger is syntactically embedded inside not, d. It ’ s possible that the course on it ’ s possible that , or an if- sentence, it behaves as if pragmatics is really challenging. ･ it wasn ’ t embedded at all: The presupposition is • Only (2a) implies something is challenging. still implied by the sentence. • But all the sentences imply there ’ s a course (2) a. The course on pragmatics is really on pragmatics. challenging. • Can test if something is a presupposition by b. The course on pragmatics isn ’ t really adding not to the sentence and seeing if it ’ s challenging. still implied. More Weird Things Other Presupposition Triggers Presuppositions Do • The: The King of France  there is a King of • A presupposition can be cancelled by: France. – overtly denying it: • Proper Names: Jo  there is someone called (2) e. The King of France didn ’ t sign the Jo. proclamation there is no King of France. • Possessives: John ’ s children  John has – the nature of the context: children  there is someone called John. (2) f. If Jo has a son, then Jo ’ s son is bald. • Stop: John stopped smoking  John smoked. g. If baldness is hereditary, then Jo ’ s son is • Realise: John realised X  X. bald. But it ’ s possible that Jo hasn ’ t got a son. • Comparatives: Jo is a better linguist than Alex  Alex is a linguist. 2

The Projection Problem (a) The Projection Problem (b) The Projection Problem: • (2) shows that working this out depends on: – Semantic content of the simple sentences that are • Suppose a sentence S contains a part of S presupposition trigger T with – Their relation to each other corresponding potential presupposition – Their relation to each other ’ s presuppositions. P. • So in our grammar, you have to look at the • Then how do we compute whether P is whole DRS built already to see if P survives as an implication. presupposed (and hence implied) by S? Using Presuppositions in Dealing With Presuppositions Communication in the Grammar To Tony Blair: So far: • (3) a. Have you broken your promises to the • The : x British People? NP • b. When did you realise that the British becomes x People would know that you have broken DET N your promises to them? name(x) the name – (3a) doesn ’ t presuppose anything. No is a good answer. – (3b)  Blair realised that the British People would • Reuse a referent if you can. Otherwise, know...  he broke the promises. introduce the referent to the top bit of the box. 3

The Rule in Action Shortcomings • the dog can talk about something old or Rule doesn ’ t say look for a dog/cat! something new, depending on the • (7) A dog chased a cat. The dog caught context. the cat. • Examples: • One DRS is: x, y • The dog ran. dog(x) cat(x) cat(y) dog(y) • A dog barked. The dog ran. chase(x, y) catch (y, x) Shortcomings Continued Yet More Shortcomings • It wont explain the projection from • We get scope ambiguity where we don ’ t embeddings: want it. • (8) If peace is settled, then the King signed • (9) Every horse jumped the fence. the proclamation. x, y king(x) [peace is settled ] ⇒ proclamation(y) sign(x, y) 4

Presuppositions Behave like Presuppositions Behave like Pronouns (a) Pronouns (b) (10) a. Jack has children and all of Jack ’ s • Presuppositions are like pronouns, but with semantic content. children/them are bald. – You try and bind it to an antecedent. b. If Jack has children, then all of Jack ’ s – But if you can ’ t bind it, then there ’ s enough children/them are bald. semantic content to add it anyway. c. Either Jack has no children or all of • Adding a presupposition to the context is known as ACCOMODATION. Jack ’ s children/them are bald. • You ’ re assuming that the presupposition is (11) All of Jack ’ s children/?them are bald. true, even though you didn ’ t know it before. Solution to the Projection Solution to the Projection Problem (a) Problem (b) 1. Replace the presupposition trigger with a This gets things right! suitable pronoun. • The presupposition is cancelled in (10) 2. If the pronoun has a suitable antecedent (i.e., and (2f ) because the pronoun is fine. the sentence is acceptable), then the • The presupposition survives in (11) and presupposition doesn ’ t survive. (2a,b,c,d) because the pronoun is odd. 3. If the pronoun doesn ’ t have a suitable antecedent (i.e., sentence sounds odd), the presupposition survives. 5

Modelling Presuppositions Summary (a) Systematically • The grammar already has mechanisms for • There are several devices in language that a binding pronouns to antecedents. speaker can use to present information as • So we can use this to handle presuppositions. though the speaker and hearer can both • But we must make sure presuppositions bind assume it is true. in the right circumstances. • Such information is called a presupposition. • And we must add mechanisms for • The things that trigger them are called accommodation. presupposition triggers. – If we ’ re accommodating a presupposition, then • Presuppositions project from embeddings. ∗ What do we add? ∗ Where in the DRS do we add it? Summary (b) Exercises • Presuppositions can be cancelled by • 1. If we couldn ﾕ t accommodate presuppositions, then just like (12a), (12b) context. would be odd, unless there was a preceding • Presuppositions behave like pronouns discourse context like (12c) that introduces a with semantic content: King of France. (12) a. ?He is bald. b. The – You try and bind it to an antecedent; King of France is bald. c. There is a King of France. The King of France is bald. Imagine a – But if you can ’ t, you accommodate it. world where you couldn ﾕ t accommodate • Viewing presuppositions this way can presuppositions. Then what sentences would solve the Projection Problem. you have to precede the following with, in order to make them acceptable: (13) a. John didn ﾕ t stop beating his wife. b. John regretted that he didn ﾕ t stop beating his wife. c. Alex 6