Linguistic Structures

CSE 140/etc.

The central hypothesis

• Human intelligence is within the set of computable functions (Turing)

• Application to language and its computational properties

Outline• Illustration of abstract linguistic representations,

beginning with phonology (sound structure) and moving to syntax (roughly = sentence structure)

• Eventually: Different perspectives on linguistic computation (mathematics, brain imaging, etc.).

• First: Establishing linguistic representations and processes.

Phonological Structure

Illustrating our tacit knowledge of abstract properties of language.

English Stress:

indePENdenttwenty-SEvenLEgislatorMissisSIppi

The Rhythm Rule

Put some of this together and we get:

TWEnty-seven MISsissippi LEgislators

• I.e., without having been taught this rule, speakers automatically calculate a shift in stress

•Not a rule like that coming from English teachers (e.g. “No split-infinitives”); part of what speakers know unconsciously

•Consider e.g. thirteen Japanese bamboo tables

Syllable Structure

Legislator: le-gi-sla-tor; four syllables ()

Onset Rhyme c

Nucleus Coda a t

Monosyllabic cat:

Onsets and Speech Errors

Spoonerisms (Rev. Dr. W. A. Spooner, 1844-1930)

Target: dear old queenOutput: queer old dean

Target: You have wasted the whole termOutput: You have tasted the whole worm.

Target: You missed my history lectures.Output: You hissed my mystery lectures.

Pig Latin

Hat > AtheyThin > IntheyStrong > OngstreyLinguistics > InguisticsleyApple > Appleey

Pattern: Add a syllable to the end of the word; copy the onset of the word-initial syllable to the onset of the word-final; add ‘ey’ to the rhyme.

Expletive Infixation

Suffix: Attached to the end of a word (work-ed)Prefix: Beginning (un-important)Infix: Inside a word; example:

Expletive infixation is fan-fucking-tastic.

Patterns

Expletive Infixation is not something that ourEnglish teachers instruct us in; yet we know a great deal about it:

*fanta-fucking-stic unrea-fucking-listic

inde-fucking-pendent *unre-fucking-alistic

*indepen-fucking-dent *unreali-fucking-stic

Abstract Metrical StructureStress placement involves computation over abstractrepresentations, and these define expletive infixation.

Syllables are grouped into feet; one syllable in the foot receives prominence (stress):

Àppalàchicóla

(Àppa)(làchi)(cóla)

E.g.

Has three binary feet ():

In which the first member of each foot is prominent.

The Rule

The placement of the expletive is governed bythe following condition:

Expletive Insertion: The expletive is inserted immediately before a non-initial stress foot of the word:

(Appa)(lachi)(cola) 1 2

Has two such junctures; so either

Appa-fucking-lachicola, or Appalachi-fucking-cola

Synopsis

•Evidence for the abstract representation of phonological units, and for the tacit knowledgeof rules governing phonological computation.

•With things like the Rhythm Rule and Expletive Infixation, native speakers know the rules withouthaving been taught.

•Moving on now to the syntactic domain, where we will find the same things; abstract representations, and implicit knowledge of computation.

Syntax

A simple defintion: the syntax of a language is the set of rules that determines word order.

Playing Devil’s Advocate: Do we need abstract structures for syntactic knowledge? Assumewe have

(1) Words, e.g. dog, yellow, defenestrate(2) Meanings

Why have syntax in addition?

The Question

Restating: Can the meanings of natural languagesentences be retrieved reliably without reference to syntactic structures?

Outline: We’ll sketch some attempts to do withoutexplicit syntactic representations, and show their problems.

Table Look-up is not feasible: 500 words, 10 word sentences:

50010 = 1027 entries...

Semantics Only?•Suppose we just added words from a sentence to a list, and attempted to determine the meaningof the sentence from this jumble.

The cat chased the rat.

How do we know from the meanings of (chased, rat, cat) that the cat was doing the chasing? We don’t… so maybe pragmatic knowledge can be added.

Semantics + Pragmatics?

Pragmatics = for present purposes, real-world knowledge and its linguistic aspects.

So for The cat chased the rat we use the fact thatcats typically chase rats (but not vice versa) to get the meaning of the sentence.

But what about

The mailman bit the dog

No amount of context can make the dog the biter here; word order is the crucial factor.

Frames for Predicates

Idea: With a predicate (verb), associate argumentswith positions around the verb. So, e.g.

Give (Agent, Patient, Recipient)

Order: Agent gave Patient to Recipient

Then: For John gave the apple to Mary, the procedure will identify the semantic roles of (John,apple, Mary) by knowing where tolook in the neighborhood of the verb give.

How This Might Operate

John gave the apple to Mary

1. Scan from left-to-right until you reach a verb2. Identify that verb’s argument frame 3. Scan back: first NP is Agent4. Scan forward from V; first NP is Patient5. Scan for NP after a preposition, and interpret it with the verb’s frame (to, Recipient)

Further Aspects of Frames• The simple dog vs. mailman problem is solved

• Some simple passive sentences can also be handled, by altering the mappings:

An apple was given to Mary by John

I.e., the frame is changed to

Patient was given to Recipient by Agent

•Notice that you have to identify be + participle inorder to know when to use the passive frame...

Problems with Frames

Searching for arguments of verbs in fixed positionsdoes not always work:

What did John give to Mary?

The apple that John gave to Mary...

In each case:

1. The verb is identified; the first NP to the left is identified as Agent2. The procedure then looks for a Patient to the right; but it is not going to find one.

What goes wrong

What did John give ( ) to Mary?

The apple that John gave ( ) to Mary...

In each case, there is a ‘gap’ in the normal positionfor the argument:

The procedure is incapable of associating the elementinterpreted in the gap position (wh-word or head ofthe relative clause) with the gap position

Filling in Gaps

Illustrating with wh-words: the relationship betweenthese elements and gaps is complex.

•In some cases, an embedding of arbitrary depthmay occur between the wh and its gap:

What did John say that Mary thought that Fredsaid that Susan believed that…

Jane ate ( ) yesterday.

Conditions on Gaps

In other cases, however, gaps are impossible in whatlook like much ‘smaller’ structures. Consider the ok pair

John said that Mary fixed the car with a wrench.How did John say that Mary fixed the car ( )

And compare it toJohn heard a rumor that Mary fixed the car with a wrench.*How did John hear a rumor that Mary fixed the car ( )?

This looks syntactic: the gap cannot be inside a complex noun phrase (the rumor that…)

Linear Order vs. Structure

Consider a sentence like

That guy is tall.

And the yes/no question variant

Is that guy tall?

Does this rule suffice?

Move the first auxiliary verb to the beginning of the sentence.

Hierarchical Structure

Consider now

The guy who is in the garden is tall.

Applying the rule above, we get

*Is the guy who in the garden is tall?

Which is clearly not what we want. The auxiliaryverb that appears at the front of the sentence is notsimply the first linearly; it is the one in a specifichierarchical position. Now for tree diagrams...

Trees

S = SentenceNP = Noun PhraseVP = Verb PhraseAP = Adjective ...

S

NPThe guy who is in the garden

VP

Vis

APtall

The linearly first is is insidethe NP Subject. Only themain is is moved in questions.