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Syntax. March 20, 2012. The Last Quick Write. Flashback. Way back when, we talked about how it’s possible to produce infinitely long sentences in a language. Example:

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March 20, 2012

  • Way back when, we talked about how it’s possible to produce infinitely long sentences in a language.
  • Example:
    • John said that Mary thought that Robin knew that Angela saw that Quinton wanted Sam to think that Becky heard that Steve wished that Forrest hoped that Bronwen believed that....
  • Idea: our knowledge of language consists of “patterns of patterns”
  • We also talked about sentences like the following...
    • Colorless green ideas sleep furiously.
    • I’m memorizing the score of the sonata I hope to compose someday.
    • ‘Twas brillig, and the slithy toves
    • Did gyre and gimble in the wabe…
  • The claim was that these were “acceptable” sentences of English, even though they made no sense.
  • In contrast, the following sentences were not acceptable:
    • Green sleep ideas furiously colorless.
    • I’m memorizing the perform of the score I sonata to hope someday.
    • Brillig and, slithy and the toves
    • Wabe gimble in the gyre and did…
  • What makes these sentences unacceptable, and the other sentences acceptable?
  • Syntax = the rules a language has for putting words together into sentences
    • also: rules for putting words together into phrases
  • Important terminology: grammatical
    • = strings of words that form possible sentences of a language
    • = conform to the syntactic rules a language has for putting words together into sentences
  • What is grammatical is based on a native speaker’s judgment of acceptability.
    • (descriptive grammar)
on the other hand
On the other hand
  • Another important term: ungrammatical
    • = string of words that is not a possible sentence in a language
    • = cannot be produced by the syntactic rules of a language
  • What is ungrammatical also reflects a native speaker’s judgments
  • Symbolized with a * before a string of words:
    • *Green sleep ideas furiously colorless.
game plan
Game Plan
  • Our goal for today:
    • Figure out some basic syntactic rules
    • i.e., how languages put words together into larger units
  • Let’s start with this observation:
  • The rules for putting words together into sentences do not necessarily yield utterances that make sense.
    • Colorless green ideas sleep furiously.
  • Q: If syntactic rules are not based on what words mean, how do they work?
lexical categories distribution
Lexical Categories: Distribution
  • The rules for putting words together into sentences operate on lexical categories (word types), not word meanings.
  • Words of each lexical category have a specific syntactic distribution:
    • = the words that may appear around them, in their “syntactic environment”
  • Also: there are restrictions on the inflectional affixes which may attach to them.
    • = “morphosyntax”
lexical categories distribution10
Lexical Categories: Distribution
  • Example: Nouns (N)
  • Semantically: refer to persons, places and things
  • Syntactically:
  • May occur after Determiners
    • this book, the water, an idea
    • *this excite, *the somber, *an exactly
  • May be modified with Adjectives
    • this funny book, the bad water, a slippery idea
  • Also, nouns can be plural:
    • the dogs, the cats, *the sombers, *the exactlys
lexical categories distribution11
Lexical Categories: Distribution
  • Verbs (V)
  • Semantically: refer to events and states of affairs
  • Syntactically: may appear after Auxiliaries
    • he can go, she will stay, I have walked
    • *he can printer, *she will strange, *I have occasionally
  • Verbs also take specific inflectional affixes:
    • He runs, She plays, It works.
    • *He printers, *She stranges, *It precipitouslies.
    • He is running, She is playing, It is working.
    • *He is printering, *She is stranging, *It is occasionallying
lexical categories distribution12
Lexical Categories: Distribution
  • Adjectives (Adj)
  • Semantically: describe things that nouns refer to
  • Syntactically: may be modified by Degree Words
    • very funny, too wet, quite slippery
    • *very building, *too walk, *quite these
  • Adjectives can also take specific inflectional affixes:
    • wetter, funniest
    • *buildinger, *walkest
lexical categories part 1
Lexical Categories, part 1
  • The familiar lexical categories are “open-class” categories…
    • It is relatively easy to add new items to the category.
  • Nouns (N): wickedness, phonology, smock, blog…
  • Verbs (V): eat, smash, insult, hug, chillax…
  • Adjective (A): creepy, red, humungous, snarky…
  • Adverb (Adv): quickly, now, sneakily…
    • Note: many adverbs are derived from adjectives.
  • But remember that category membership can be fluid...
    • Ex: Calvin’s verbing of nouns
lexical categories part 2
Lexical Categories, part 2
  • Other lexical categories are “closed-class” or functional categories…
    • It is very difficult to add new items to the category.
  • Prepositions (P): to, in, on, near, at, by…
  • Pronouns (Pro): I, you, he, she, we, they, it…
  • Auxiliaries (Aux): will, can, may, must, should, could…
  • Determiner (Det): a, the, this, those, my, their…
  • Conjunction (Con): and, but, or…
  • Degree (Deg): too, so, very, more, quite…
  • The meaning of these categories is harder to define; their function is to help string words in a sentence together.
check it out
Check it out!
  • Words can be categorized on the basis of distributional and morphosyntactic evidence...
  • Even if they don’t mean anything:
  • 'Twas brillig, and the slithy toves
  • did gyre and gimble in the wabe.
  • All mimsy were the borogoves,
  • And the mome raths outgrabe.

Pro V A Con Det A N

V V Con V P Det N

Det A V Det N

Con Det A N V

twas brillig
‘Twas Brillig?
  • “Brillig” is actually in the appropriate syntactic frame for either an adjective or a noun.
  • “It was pleasant…”
  • “It was evening…”
  • “It was four in the afternoon….”
a first hypothesis
A First Hypothesis
  • How do we put words together into (grammatical) sentences?
  • A really simple way = string one word category after another:
  • S  Det N V Det N
      • ( = “may consist of”)
  • The child found a puppy.
  • S  Det A N V P Det N
    • The slithy toves gimbled in the wabe.
  • These syntactic rules could capture patterns of words.
important data
Important Data
  • What’s going on in these sentences?
  • We need more intelligent leaders.
  • I like green eggs and ham.
  • The police shot the terrorists with rifles.
  •  Syntax also puts words together in units that are smaller than sentences.
    • These units are called phrases.
  • Same string of words, more than one interpretation =
    • more than one phrase structure
    • structural ambiguity
actual newspaper headlines
Actual Newspaper Headlines
  • One way in which syntax can enrich your life is through unintentional humor.
ambiguity again
Ambiguity (again)
  • There are two ways to represent structural ambiguity in sentences.
  • Method 1: Bracketing
    • [more intelligent] leaders
    • more [intelligent leaders]
  • Just like morphological bracketing:
    • [[unlock]able]
    • [un[lockable]]
ambiguity again21
Ambiguity (again)
  • Method 2: Phrase Structure Trees
  • more intelligent leaders
  • more intelligent leaders
tree terminology
Tree Terminology
  • more intelligent leaders
  • more intelligent leaders

root node



ambiguity continued
Ambiguity (continued)
  • Recall: in morphology, each node in a tree had to be a real word
  • Adj
  • Adj
  • Aff Verb Aff
  • [un-] [lock] [-able]
  • = not able to be locked
ambiguity continued24
Ambiguity (continued)
  • Recall: in morphology, each node in a tree had to be a real word
  • Adj
  • Verb
  • Aff Verb Aff
  • [un-] [lock] [-able]
  • = able to be unlocked
  • The nodes in a syntactic tree above the word level represent phrases.
    • phrase = string of words that function as a unit
  • Basic phrase types:
    • Noun Phrases (NP): [intelligent leaders]
    • Verb Phrases (VP): [shoot terrorists]
    • Prepositional Phrases (PP): [with rifles]
    • Adjective Phrases (AP): [more intelligent]
phrase phacts
Phrase Phacts
  • Every phrase has to have at least one constituent
    • This constituent is called the head of the phrase.
  • The head determines the phrase’s function, behavior and category.
  • For example, noun phrases have to consist of at least one noun.
    • Robin the book
    • a picture of Robin a picture of the unicorn
    • that weird picture of Bob’s unicorn
in general
In General
  • There’s a pattern to how these things work:
  • Noun phrases (NPs) are headed by nouns
    • NP  N
  • Verb phrases (VPs) are headed by verbs
    • VP  V
  • Prepositional phrases (PPs) are headed by prepositions
    • PP  P
  • Adjective phrases (AdjP) are headed by adjectives
    • AP  A
  • Basic Phrase Structure Rule: XP  X
more about phrases
More About Phrases
  • Beyond the heads, phrases can be expanded with specifiers and complements.
  • Specifiersprecede the head of the phrase;
    • they qualify or pick out a particular version of the head.
  • Examples:
  • this book (Determiner specifying noun)
  • very late (Degree word specifying adjective)
  • often forgets (Qualifier/Adverb specifying verb)
  • almost in (Degree word specifying preposition)
  • Complements always follow the head of the phrase…
    • And provide more information about that head.
  • this book about unicorns
    • PP complement of the head of the NP.
  • very late to class
    • PP complement of the head of the AP.
  • often forgets his hat
    • NP complement of the head of the VP.
  • almost in the basket
    • NP complement of the head of the PP.
x bar theory
X-Bar Theory
  • Together, heads and their complements form a phrasal structure known X’ (“X-bar”).
  • Here’s the way phrases (of all kinds) normally break down:
  • XP
  • (Specifier) X’
  • X (Complement)
  • Head
  • note: heads are the only obligatory element in the phrase
  • optional stuff is in parentheses