LIN 1180 Semantics Lecture 8 Albert Gatt Part

LIN 1180 – Semantics Lecture 8 Albert Gatt

Part 1 Hyponymy and other relations

Definition of hyponymy o Hyponymy is a relation of inclusion. o Arrows can be interpreted as “ISA” relations. o Unlike taxonomic sisterhood, which is horizontal, hyponymy is vertical. LIN 1180 -- Semantics ANIMAL BIRD CANARY MAMMAL SPARROW

Elements of hyponymy �If Y IS-A X then: �X is the superordinate or hypernym of Y �Y is a subordinate or hyponym of X �e. g. HUMAN is the hypernym of MAN, TOOL is the hypernym of CHAINSAW �Inclusion: �if Y is a hyponym of X then Y contains the meaning of X (plus something extra) �e. g. MAN includes all the features of HUMAN, plus the specification of ADULT and MALE. �Transitivity: �if X IS-A Y and Y IS-A Z, then X IS-A Z LIN 1180 -- Semantics

Transitivity -- illustration �A CANARY IS-A BIRD �A BIRD IS-A ANIMAL �Therefore, a CANARY IS-A ANIMAL LIN 1180 -- Semantics ANIMAL BIRD CANARY MAMMAL SPARROW

Hierarchical representations and inheritance �A node in a conceptual network inherits some properties from its superordinate BIRD �It can also add new properties of its own �It can override properties of OSTRICH the superordinate Semantics -- LIN 1180 ANIMAL Moves Eats breathes Flies Has feathers Does not fly

Levels of conceptual representation �Rosch et al. 1976 propose 3 levels FURNITURE CHAIR ARMCHAIR Superordinate Or “top” level TABLE Basic level: This is the level we tend to use and think about Subordinate level: Much more specific Semantics -- LIN 1180

Properties of the basic level 1. The easiest to visualise: � 2. Used for neutral, everyday usage: � 3. easier to imagine a CAR (basic) than a FIAT PUNTO (subordinate) we’re more likely to say “that’s a dog” than “that’s a dachshund” or “that’s an animal” Names of basic-level categories tend to be morphologically simple � Compare: spoon vs. teaspoon, soup spoon… Semantics -- LIN 1180

More properties of the basic level 4. high distinctiveness o 5. strong within-category resemblance o 6. maximally different from other categories objects within the category resemble eachother more than they do objects outside the category optimal level of informativeness: it’s more informative to say “x is a dog” than “x is an animal” o but in most cases, saying “x is a dachshund” is too specific… o Semantics -- LIN 1180

Special cases of taxonomic relations � Sometimes, language exhibits special cases of relations that are: �well-established and lexicalised �seem to depend on an underlying taxonomy or hierarchy � ADULT-YOUNG �dog – puppy, duck – duckling, etc � MALE-FEMALE �woman – man, dog – bitch, drake – duck, etc � NB: These pairs are often asymmetric. The unmarked case in the MALE-FEMALE is the MALE. �We tend to use it for the name of the species. LIN 1180 -- Semantics

Meronymy or part-whole �A different kind of taxonomic relationship. Arrows are interpreted as “HAS-A” ANIMAL LEG HAS-A IS-A BIRD WING HAS-A LIN 1180 -- Semantics

Meronymy vs. Hyponymy � Meronymy tends to be less regular than hyponymy: �NOSE is perceived as a necessary part of a FACE �CELLAR may be part of HOUSE, but not necessarily � Meronymy need not be transitive: �If X HAS-A Y and Y HAS-A Z, it does not follow that Y HAS-A Z � window HAS-A pane � room HAS-A window � ? ? room HAS-A pane � Common-sense knowledge plays a very important role in acceptability of these relations. LIN 1180 -- Semantics

Member-collection relations �We often lexicalise names of collections of specific things: �flotta (fleet) : a collection of ships �merħla (flock): a collection of sheep �Native speakers know there is a member- collection relation: �flotta (fleet) – vapur (ship) �armata (army) – suldat (soldier) �merħla (flock) – nagħġa (sheep) �Can be viewed as a special, lexicalised case of meronymy. LIN 1180 -- Semantics

Are collections singular or plural? �In many languages, there is the possibility of switching from: �a view of a collection as a single entity vs. the “contents” of the collection as a group or set �English: �The band played well tonight. �It drove the crowd nuts [SG] �They drove the crowd nuts [PL] �Maltese: � L-armata rtirat (The army retreated. SG) �? L-armata rtiraw. (The army retreated. PL) �Perhaps not as acceptable? Only with some nouns? LIN 1180 -- Semantics

Part 2 Beyond the lexicon: Overview of sentence relations

In this lecture �Having looked in some detail at properties of the lexicon, we now turn to sentences. �We discuss �meaning relations between sentences �truth conditions �presupposition LIN 1180 - Semantics

Sentence relations �Just as lexical items stand in various relations to one another (hyponymy, etc), so do sentences: �Relations between sentences arise due to: �the lexical items in them �their grammatical structure LIN 1180 - Semantics

Sentence synonymy 1. 2. My brother is a bachelor My brother is an unmarried man � (1) and (2) seem to have the same meaning (or almost. . . Cf. Our discussion of synonymy) LIN 1180 - Semantics

Entailment 1. 2. My sister assassinated the president. The president is dead. � (1) entails (2), primarily because of the meaning of assassinate. � if (1) is true, then (2) must be true � The following are not in an entailment relationship: 3. My sister shot the president. 4. The president is dead. � If (1) is negated, it no longer entails (2): � My sister did not assassinate the president. LIN 1180 - Semantics

Important properties of entailment �A sentence p entails a sentence q if, and only if: �q is true whenever p is true �q is false whenever p is false �This is why entailment is cancelled by negation. LIN 1180 - Semantics

How does entailment arise? �Lexical, e. g. hyponymy �My sister assassinated X X died. �assassinate Y includes Y dies �I bought a dog I bought an animal �dog is a hyponym of animal �Syntactic, e. g. active/passive �My sister assassinated the president The president was assassinated by my sister. LIN 1180 - Semantics

Contradiction 1. 2. My canary has just escaped from its cage. My canary has never been in a cage. � If (1) is true, then (2) cannot be true (and vice versa) � 3. (2) contradicts (1) He is a murderer but he’s never killed anyone. o (3) is also a contradiction LIN 1180 - Semantics

Tautology 1. 2. Albert is Albert This classroom is this classroom. � Both (1) and (2) are necessarily true � In fact, both are highly uninformative sentences. LIN 1180 - Semantics