SyntaxConstituency, Phrase structure rules

LING 400

Winter 2010

Overview

• What is syntax?

• Tree structures

• Ambiguity

• Phrase structure rules

• Recursion

please turn off and put away your cell phone

What is syntax?

• Organization of words into phrases and sentences– “Husky pride never takes a time out.”– *Husky pride time out a never takes.

• What’s a sentence?

Linguists try to describe syntactic competence

• What speakers/signers know– possible phrases and sentences– impossible phrases and sentence– meanings of phrases and sentences

Tree structuresTrees show syntactic organization

P: Preposition: on, from, to, under, in, …

NP: Noun phrase

PP: Prepositional phrase– Dinner cooked on the grill.

Trees vs. labeled brackets

Tree structure:

Labeled bracketing: PP[P NP]

Terms

constituentsyntactic unit consisting of one or more words

node root nodebranching node

terminal nodes

Words and tree structures

learn [lɹ̩ �n]

learnable [ˈlɹ̩ �nəbl̩ �]learnability [lɹ̩ �nəˈbɪl̩ɪɾi]

Compositionality

• (Extent to which) meanings of words, phrases determined by– morpheme meaning– structure

Ambiguity

• = “having more than one meaning”

• Sources of ambiguity– different meanings of same morpheme

• hard ‘solid, difficult’

– homophonous morphemes• bank

– structure– more than one of above

An ambiguous headline

• HERSHEY BARS PROTEST – [Hershey bars] protest

– Hershey [bars protest]

An ambiguous word: unfoldable

‘not capable of being folded’ ‘capable of being unfolded’

un- negative: Adj[___Adj[ un- ‘reverse’: V[___V[

Phrase structure rules

• Rules which create tree structures

• PP P NP

• (“PP consists of/is P NP”)

creates

Recursion

Long sentences: This is the house that Jack built.This is the malt

that lay in the house that Jack built.This is the rat

that ate the maltthat lay in the house that Jack built.

...

This is the priest all shaven and shornthat married the man all tattered and tornthat kissed the maiden all forlornthat milked the cow with the crumpled hornthat tossed the dogthat worried the catthat killed the ratthat ate the maltthat lay in the house that Jack built.

...

• Phrase structure rules– specify word order

– are recursive • output of one rule can be rewritten via another rule

• Rules which generate The House that Jack Built– NP NP S’

– S’ Comp S

– S NP VP

– VP V NP

How to characterize infinity?

More phrase structure rules

S = sentenceVP = verb phraseS NP VPNP NVP V 

More phrase structure rules

NP (Det) (Adj+) N (PP)Det = determiner

Adj = adjective

N = noun

() = optional+ = one or more

Determiners vs. adjectives

• Det a/an, some, the, that, your (etc.)• One determiner per NP (in English)

– your truck, the truck

– *your the truck, *the your truck

• Adj big, stupid, green (etc.)• More than one Adj possible

– big trucks, big stupid trucks, stupid big trucks

• Det precedes Adj– his stupid truck

Count vs. mass nouns• ‘chair’ (count) vs. ‘furniture’ (mass)• plural form? chairs, *furnitures• a__

– a chair– *a furniture

• every__– every chair– *every furniture (every bit of furniture)

• much__– *much chair (many chairs)– much furniture

• enough__– *enough chair (enough chairs)– enough furniture

• bare noun– *I want chair.– I want furniture.

• the__– the chair– the furniture

• some__– some chair– some furniture

‘dinner’ (both)

A Noun Phrase

Summary

• Syntactic competence

• Tree structures

• Ambiguity

• Phrase structure rules

Question

• What are the two meanings in this ambiguous headline?

HOSPITALS ARE SUED BY 7 FOOT DOCTORS