Linguistics Types of Grammars Types of Grammars Chomsky Hierarchy

Linguistics Types of Grammars

• Phonology – sound • Type 0 Grammars • Morphology – word composition – No restrictions on rules: rules may be recursive, and any number of symbols may occur on either side of a • Syntax – structure rule • Semantics – meaning • Type 1 Grammars Context-Sensitive Grammars • Pragmatics – implications – Grammars in which every rule is of the form σAτ Æ σφτ – Where A is nonterminal and σ and τ are arbitrary strings of terminals and nonterminals, with φ nonempty

Types of Grammars Chomsky Hierarchy

•Type 2 Context-Free Grammars • Type 0 – Grammars in which every rule is of the form – Recursively Enumerable Grammar A Æ φ – Turing Machine – Where A is a nonterminal and φ is an arbitrary • Type 1 nonempty string of terminals and nonterminals – Context-Sensitive •Type 3 Finite State Grammars Grammar – Grammars in which every rule is of the form Type 3 – Linear Bounded Automata • Type 2 A Æ xB or A Æ x Type 2 – Context Free Grammar – A and B are single nonterminals – Pushdown Automata – x is an arbitrary string of terminals Type 1 • Type 3 – Finite State Grammar Type 0 – Finite State Automata

Ice Cream Sentences Either the boy Ice cream

• Either the girl eats ice A If B a C girl D eats E Hot dogs F

cream, or the girl eats candy one candy. dog then • If the girl eats ice cream, then the boy eats hot dogs. AÆ Either B BÆ the C CÆ boy D If B a C girl D one C dog D D Æ eats E E Æ ice cream F F Æ or B hot dogs F then B candy F

1 FSG can’t account for ice Embedded English Sentences cream! Either the girl eats ice •Ifeither the girl eats ice cream or the girl cream, or the girl eats candy. eats candy then the boy eats hot dogs. If the girl eats ice cream, then the boy eats hot dogs. *Either the girl eats ice cream, then the boy eats hot dogs. *If the girl eats ice cream or the girl likes candy.

Embedded English Sentences Deep Structure, Surface (Dependencies) Structure • Daddy, what did you bring that book I don’t The cat chased the mouse. The mouse was chased by want to be read to out of up for? the cat. •HowAnn can claim Pam Dawber’s anger Active: at not receiving her fair share of acclaim Deep = Surface Structure Structure for Mork and Mindy’s success derives from Passive: a fragile ego escapes me. Deep structure undergoes transformation NP1 V NP2 Æ NP2 was V’d by NP1

NP Aux VP Æ Aux NP VP D-structure

The cat did chase the • Linguists posit d-structure mouse. to account for the way Did the cat chase the verbs change in different mouse? contexts He put the car in the The cat is chasing the garage. mouse. *He put the car. Is the cat chasing the *He put in the garage. mouse. The car was put in the garage. The mouse could have been What did he put in the chased by the cat. garage? Could the mouse have been Where did he put the car? chased by the cat?

2 Movement and Traces Parsing

• Parse Tree – represents how grammatical structure has been assigned to the string • Parsing process does 2 things: – Determines which sentences are grammatical and which are not – For grammatical sentences, assigns a structure

Syntactic Ambiguity High Attachment (man’s leg)

• Syntactic Ambiguity – Sentences or phrases that have 2 or more interpretations because there are multiple ways to parse them • The old man in the chair with the broken leg

Low Attachment (chair’s leg) Garden Path Sentences

• Sentences in which your initial parse is likely to be wrong

NP VP

Det Adj N

The old train the

3 Correct Parse Garden Path Sentences

• Sentences in which your initial parse is likely to S be wrong NP VP S Det N V NP NP VP SCREECH!!! Det N Det Adj N The old train the young. The old train the

Linguistics Semantics & Pragmatics

• Phonology – sound • Semantics – Study of how meaning is • Morphology – word composition specified in words, sentences, texts • Syntax – structure • Reference Theory (problematic) • Semantics – meaning – Meaning of word is what it refers to in the world • Pragmatics – implications •Unicorn • Jerry hunted a tiger. •Justice •The • Morning star vs. Evening Star

Semantic Theories Truth Conditional Semantics

• Image Theory (overly • Truth Conditional (Formal) Semantics simplistic) – Conditions that have to hold for a word to be true – Meaning of a word is an constitute its meaning image •Truth – Word Meaning: necessary and sufficient conditions •the for category membership • Cognitive Semantics – Sentence Meaning: set of conditions that have to hold – Words refer to elements in for sentence to be true simple cognitive models • Problem: human establishment of truth – Locates meaning in cognitive processes conditions for complex sentences doesn’t always • She gave her hotdog to follow rules of logic the hungry boy. • She gave her hotdog to a hungry boy.

4 Psychologists & Semantics Pragmatics

• “Loose” truth-conditional semantics • Study of meaning in context – Prototypes & Exemplars constitute “truth • Cooperativeness Principle conditions” for words – Speakers and listeners must be cooperative • Cognitive Semantics in order for successful communication to – Meaning established with respect to occur knowledge of prototypes, exemplars, & • Conversational Maxims frames – Guidelines followed by cooperative speakers – Comprehension involves construction of mental models

Grice’s Conversational Maxims Disobedience

• Maxim of Quantity • Maxim of Manner • People frequently flout – Make your contribution as – Be perspicuous* the maxims informative as required for • Avoid obscurity of – Speaker deliberately the current purpose of the expression violates a maxim exchange • Avoid ambiguity – Listener assesses nature of – Do not make your • Be brief (avoid violation in current context unnecessary prolixity) contribution more – Listener computes informative than is required • Be orderly implicature • Maxim of Quality • Maxim of Relation •Implicature – Try to make you – Be relevant – Inferences a listener draws contribution one that is true *“perspicuous” means clear when a speaker blatantly – Do not say what you and easy to understand violates one of the maxims believe to be false – Do not say that for which you lack relevant evidence

Maxims & Conversation Maxim of Quantity

• Quantity most important “the black one” • Supposition – Making contact with concepts in the “the round one” listener’s memory • Assertion – Changing the structure around these concepts “the round, black one”

5 Quantity Common Ground

• Olson – amount that needs to be said • Mutual suppositions, beliefs, and depends on context knowledge The boy is a good soccer player. Willie bought Tom’s old Bug. The boy with curly hair is a good soccer player. Dr. Smith bought the orange car parked outside your office. “Consider the stallion.”

How do referents enter common Speech Acts ground? • Physical Co-Presence • Locutionary Force – Effect derived from literal • Linguistic Co-Presence meaning • Illocutionary Force • Cultural Co-Presence – Effect derived from speaker’s goal – Promise, insult, inquire • Perlocutionary Force – Intended or unintended effect of statement – Enter contract, sentence prisoner to jail

Five Types of Speech Acts

• Representatives – My desk has disappeared. • Directives – Stop putting things on my desk. • Commissives – If you put anything else on my desk, I’m throwing it in the trash. • Expressives – I’m happy it’s raining today. • Declarations – You’re fired!