Syntax 1Syntax 1

Ling400Ling400

What is syntax?What is syntax?

• the study of the internal structure of the study of the internal structure of sentences: how to put together words to sentences: how to put together words to form sentencesform sentences

• Noam Chomsky’s theory of syntax: Noam Chomsky’s theory of syntax: accounts for the productivity of our accounts for the productivity of our utterances in terms of structure-building utterances in terms of structure-building rules (phrase structure rules)rules (phrase structure rules)

Chomsky’s ThesisChomsky’s Thesis

• We can utter and/or understand an We can utter and/or understand an infinite number of sentences.infinite number of sentences.

• We can do this despite the fact that our We can do this despite the fact that our brain can store only a finite amount of brain can store only a finite amount of information. We have a rule system (i.e. information. We have a rule system (i.e. grammar) in our brain.grammar) in our brain.

• But we are not born with English But we are not born with English grammar. It is acquired.grammar. It is acquired.

Chomsky’s Thesis (continued)Chomsky’s Thesis (continued)

• We are born with a system (called We are born with a system (called Universal Grammar) which enables us Universal Grammar) which enables us to acquire any language to which we to acquire any language to which we are exposed.are exposed.

• By studying grammars of various By studying grammars of various languages, we get insight into how languages, we get insight into how Universal Grammr is structured.Universal Grammr is structured.

Syntax is independent of Syntax is independent of Semantics (though related).Semantics (though related).

• Colorless green ideas sleep furiously.Colorless green ideas sleep furiously.(grammatical but semantically deviant)(grammatical but semantically deviant)

• *Furiously sleep ideas green colorless.*Furiously sleep ideas green colorless.(ungrammatical and meaningless)(ungrammatical and meaningless)

• *The boy quickly in the house the ball *The boy quickly in the house the ball found.found.(ungrammatical but meaningful)(ungrammatical but meaningful)

How do we start?How do we start?

• We rely on our grammaticality We rely on our grammaticality judgments in doing syntactic study.judgments in doing syntactic study.

• We strive to propose a system that We strive to propose a system that produces all and only grammatical produces all and only grammatical sentences in English (or any other sentences in English (or any other lang.)lang.)

Syntactic CategoriesSyntactic Categories

• Knowledge of languageKnowledge of language– Represented by your syntactic knowledgeRepresented by your syntactic knowledge

• Syntactic categoriesSyntactic categories– Lexical categories (i.e. word-level categories): Lexical categories (i.e. word-level categories):

noun, verb, adjective, preposition, etc.noun, verb, adjective, preposition, etc.– Phrasal categories: NP, VP, AP, PP, etc.Phrasal categories: NP, VP, AP, PP, etc.

• Phrase structurePhrase structure– Syntactic composition of phrasesSyntactic composition of phrases– Structural ambiguityStructural ambiguity

ConstituentsConstituents

• A set of adjacent words that can form a A set of adjacent words that can form a meaningful unit and can be replaced by meaningful unit and can be replaced by a pro-form (e.g. pronouns) and/or a pro-form (e.g. pronouns) and/or moved as a unit are said to form a moved as a unit are said to form a constituent.constituent.

• A constituent can consists of just one A constituent can consists of just one word or multiple words.word or multiple words.

Lexical CategoriesLexical Categories

• The The boyboy seessees some very some very prettypretty flowersflowers..– perceivesperceives lovelylovely

– smellssmells smallsmall

• He He putsputs the the flowersflowers on on a a greengreen tabletable..

– purplepurple hydrangeashydrangeas underunder pinkpink posterposter

• NounNoun VerbVerb Preposition Preposition AdjectiveAdjective• There are four major syntactic categories of There are four major syntactic categories of

open-class lexical items.open-class lexical items.

Syntactic categoriesSyntactic categories

• Lexical categories: N, V, A, P, Det, etc.Lexical categories: N, V, A, P, Det, etc.

• Phrases: NP, VP, AP, PPPhrases: NP, VP, AP, PP

(XP reads ‘X phrase, where X is the (XP reads ‘X phrase, where X is the “main item”. We will study this in detail “main item”. We will study this in detail on Wednesday.) on Wednesday.)

• Constituents may be represented Constituents may be represented hierarchically as trees.hierarchically as trees.

How to find constituentsHow to find constituents

Subj.Subj. verb. verb. Obj.Obj.

JohnJohn met met Mary.Mary.

The tall boyThe tall boy met met the tall girlthe tall girl..

A boy from SeattleA boy from Seattle met met a girl from Chicagoa girl from Chicago..

A boy from SeattleA boy from Seattle met met the tall girlthe tall girl..

JohnJohn met met a student who majors in mathematicsa student who majors in mathematics..

What is subject? Something that the main verb agrees What is subject? Something that the main verb agrees with.with.

rules of thumbrules of thumb

• answers to questionsanswers to questions

• substitution (pronouns, names, do, etc.)substitution (pronouns, names, do, etc.)

• clefting (It was … that …)clefting (It was … that …)

• coordinationcoordination

Two Types of AmbiguityTwo Types of Ambiguity

• Ambiguity = multiple meaningsAmbiguity = multiple meanings

• Lexical AmbiguityLexical Ambiguity– I’ll meet you by the I’ll meet you by the bankbank..

• 1. A financial institution1. A financial institution• 2. A river bank.2. A river bank.

• Structural AmbiguityStructural Ambiguity– due to different syntactic structures due to different syntactic structures

associated with the same “string of words”associated with the same “string of words”

Structural ambiguityStructural ambiguity

I hate raw fish and onions

Give an unambiguous paraphrase.Give an unambiguous paraphrase.

Structural ambiguityStructural ambiguity

I hate raw fish and onions

Structural ambiguityStructural ambiguity

I hate raw fish and onions

Give a second unambiguous paraphrase.Give a second unambiguous paraphrase.

Structural ambiguityStructural ambiguity

I hate raw fish and onions

Structural ambiguityStructural ambiguity

The price includes soup or salad and french fries

Draw two distinct trees for the blue Draw two distinct trees for the blue portion of the sentence. portion of the sentence. Then provide paraphrases.Then provide paraphrases.

Structural ambiguityStructural ambiguityThe price includes soup or salad and french fries

For this price, you get french fries. And you can For this price, you get french fries. And you can also get soup or salad.also get soup or salad.

Structural ambiguityStructural ambiguity

The price includes soup or salad and french fries

The other possibility? Draw a tree andThe other possibility? Draw a tree andprovide a paraphrase.provide a paraphrase.

Structural ambiguityStructural ambiguityThe price includes soup or salad and french fries

For this price, you get soup. Alternatively, you getsalad and french fries.

More examples of structural More examples of structural ambiguityambiguity

(1)(1)I killed the king with a knife.I killed the king with a knife.

ambiguousambiguous

(2) I killed the king with the red hair.(2) I killed the king with the red hair.

unambiguousunambiguous