Presentation on theme: "Linguistic Structures CSE 140/etc.. The central hypothesis Human intelligence is within the set of computable functions (Turing) Application to language."— Presentation transcript:
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: indePENdent twenty-SEven LEgislator MissisSIppi
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 queen Output: queer old dean Target: You have wasted the whole term Output:You have tasted the whole worm. Target:You missed my history lectures. Output:You hissed my mystery lectures.
Pig Latin Hat >Athey Thin >Inthey Strong> Ongstrey Linguistics> Inguisticsley Apple>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 our English 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 Structure Stress placement involves computation over abstract representations, 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 by the 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 knowledge of rules governing phonological computation. With things like the Rhythm Rule and Expletive Infixation, native speakers know the rules without having 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? Assume we have (1) Words, e.g. dog, yellow, defenestrate (2) Meanings Why have syntax in addition?
The Question Restating: Can the meanings of natural language sentences be retrieved reliably without reference to syntactic structures? Outline: We’ll sketch some attempts to do without explicit syntactic representations, and show their problems. Table Look-up is not feasible: 500 words, 10 word sentences: 500 10 = 10 27 entries...
Semantics Only? Suppose we just added words from a sentence to a list, and attempted to determine the meaning of 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 that cats 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 arguments with 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 to look 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 verb 2. Identify that verb’s argument frame 3. Scan back: first NP is Agent 4. Scan forward from V; first NP is Patient 5. 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 in order to know when to use the passive frame...
Problems with Frames Searching for arguments of verbs in fixed positions does 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 Agent 2. 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 position for the argument: The procedure is incapable of associating the element interpreted in the gap position (wh-word or head of the relative clause) with the gap position
Filling in Gaps Illustrating with wh-words: the relationship between these elements and gaps is complex. In some cases, an embedding of arbitrary depth may occur between the wh and its gap: What did John say that Mary thought that Fred said that Susan believed that… Jane ate ( ) yesterday.
Conditions on Gaps In other cases, however, gaps are impossible in what look 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 to John 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 auxiliary verb that appears at the front of the sentence is not simply the first linearly; it is the one in a specific hierarchical position. Now for tree diagrams...
Trees S = Sentence NP = Noun Phrase VP = Verb Phrase AP = Adjective... S NP The guy who is in the garden VP V is AP tall The linearly first is is inside the NP Subject. Only the main is is moved in questions.