Phrase Structure Rules

• Must allow all and only the grammatical sentences in a language

• Descriptive rules, not necessarily prescriptive

• Each rule “rewrites” a constituent into one or more constituents

A Simple Set of Phrase Structure Rules

S NP +VP

NP art + (adj*) + N

VP V + NP + (PP*)

PP Prep + NP

N sailor, cat, horse, bridge,

V saluted, kissed, fried

adj drunken, puzzled, gregarious

art a, the

prep on, under

From this simple set of rules we can generate many, many sentences, including:

A cat saluted a horse.

A cat saluted a horse on the bridge.

A gregarious horse fried the cat.

The drunken sailor saluted the puzzled cat.

The puzzled, gregarious sailor on a horse saluted the drunken cat on the bridge.

Phrase Structure Tree:Derivation of a Sentence

S

NP VP

art adj N V NP

The drunken sailor saluted art adj N

the puzzled cat

Sentences with ambiguous meanings have different phrase structure trees

S

NP VP

adj N aux V adj

Visiting relatives can be boring

SNP VP

Ger N aux V adj

Visiting relatives can be boring

Transformational Rules

• Rules that transform deep structure into surface structure

• Apply to constituents not to individual words

• Involve movement, insertion, and deletion of constituents

• Conditions of occurrence: Transformations will not apply under all conditions

Some Transformations

• Particle-movement– “John called up the woman.”

– “John called the woman up.”

• T1” V + part + NP V + NP + part – John called up the interesting woman up.

– John called the interesting woman up.

– John called up the woman with the curly hair.

– John called the woman with the curly hair up.

– *John called the woman up with the curly hair.

Other Transformations

• Passive:– Arlene played the tuba.– The Tuba was played by Arlene.– T2 NP1 + V + NP2 NP2 + be +V + –en by

+ NP1

•Wh- Question: Why is Arlene playing the tuba?

•Negation: Arlene is not playing the tuba?

•Compound: Arlene is playing the tuba and the drums.

Derivational Theory of Complexity

• If transformational grammar is how language is actually done, then– Untransformed sentences > transformed sentences – Simpler transformations > complex transformations– Should see this both in acquisition and in adult

processing of sentences– But there are many exceptions to this prediction– Compound Sentences

• “The zoo has llamas and gnus” is derived from “The zoo has llamas and the zoo has gnus.”

Whence Transformational Grammar?

• Revolutionary approach to the study of language, though the specifics have not stood up well. Revised approaches include

• Parameter Setting (Chomsky, 1981, 1986, 1995)– All possible linguistic variations are hard-wired, the

parameters that are set depend on exposure to language.

• Lexical-Functional Grammars (Bresnan, 1982, Pinker, 1984, 1990)– Grammar is actually in the lexicon, e.g. an entry for a

verb entails its argument structure and restrictions as well as meaning.