Midterm Exam Nov. 2 1pm to 4pm

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Midterm Exam Nov. 21pm to 4pm

• Room 3002 NSH
• Open book
• But no internet or cell phone
• May bring food.
• May step outside to smoke.
• May go to restrooms.
• May ask questions.

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Summary Parts of Speech

• Claim
• Parts of speech can be defined by
• Distribution where they appear
• Morphology which prefixes, suffixes, etc apply
  to them
• Each criterion of distribution or morphology is
  called a test.
• Methodology
• Identify relevant tests
• Apply tests
• Judge grammaticality
• Interpret results

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Annotation

• The Test methodology is state of the art for
  annotation projects, including many treebanking
  projects.

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Trees and Constituents

• Grammars and Lexicons
• 11-721
• September 10, 2007

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Phrasal Categories
Sentence
Verb Phrase
Prepositional Phrase
Adjective Phrase
Noun Phrase
Noun Phrase
Det Noun Modal Verb Adverb Adjective
Prep. Det Noun
This boy must seem incredibly stupid to
that girl.
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Phrasal Categories

• NP Noun Phrase
• VP Verb Phrase
• PP Prepositional Phrase
• AP Adjective Phrase
• AdvP Adverb Phrase
• S Sentence

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Tree Terminology

• Mother
• Daughter
• Sister
• Dominate
• Immediately Dominate
• Node (branching or non-branching)
• Branch
• Terminal Node/Leaf Node
• Phrasal Nodes (non-terminal)
• Lexical Nodes (pre-terminal)

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Constituent

• A constituent is a string of words such that
  there is one node that dominates those words and
  no other words.

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S
Tree 1
NP
N V P Det N
Sam climbed up the ladder.
S
Tree 2
VP
NP
NP
V
N V P Det N
Sam picked up the ladder.
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Discussion

• What are the constituents of Tree 1 and Tree 2?
• Which strings of words are constituents in one
  tree but not the other?

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Coordination as a diagnostic test for constituency

• To test whether a string of words s1 is a
  constituent, conjoin it using and with another
  string which
• Is an uncontroversial constituent of the same
  category as s1 or
• (If you dont have a hypothesis about the
  category of s1), has the same part of speech
  sequence as s1

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Applying the coordination test

• Sam climbed up the ladder and out the window.
• Sam picked up a ladder and out some new
  boots.

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Movement as a test for constituency

• A constituent might appear in different positions
  in a sentence, but stay in one piece.
• There are different movement rules that affect
  different constituents (NP, PP, AP, VP).

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Begin side track for some extra background
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Transformational Grammar and Movement Rules
S
S
Meaning preserving tree-to-tree mapping
NP VP
NP VP
The chocolate V PP
The kids V NP
was eaten by the kids
ate the chocolate
Surface Structure
Deep Structure
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Transformational Grammar

1. Sentences that mean the same thing have the same
   deep structure.
2. Tree-to-tree mappings convert deep structure
   trees into surface structure trees.
3. Tree-to-tree mappings must be meaning preserving,
   so that (1) remains true.
4. Government and Binding Theory and the Minimalist
   Program (Chomsky) are theories that characterize
   which tree-to-tree mappings are meaning
   preserving.
5. The kids ate the chocolate.
6. The chocolate was eaten by the kids. (meaning
   preserving)
7. The chocolate ate the kids. (not meaning
   preserving)

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Non-Transformational Grammar

• In this class, we will not use transformational
  grammar.
• There will be no tree-to-tree mappings. (There
  will be other kinds of mappings.)
• The canonical representation of meaning will not
  be a deep structure tree.
• There will be a different way to connect
  sentences that mean the same thing.

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Movement is still a useful metaphor at this stage
in the course

• Sam climbed up a ladder.
• Up a ladder Sam climbed up a ladder.
• Sam likes chocolate.
• It is chocolate that Sam likes chocolate.

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End side track
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To use movement as a test for constituency

• First, identify a meaning preserving movement
  rule (tree-to-tree mapping).
• Give an example showing this movement rule
  applying to an uncontroversial example
• Sam ran into the room.
• Into the room Sam ran.

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Applying the movement test

• Then apply the same rule to a controversial
  example that you want to test.
• Sam climbed up a ladder.
• Up a ladder Sam climbed. passes the test
• Sam Picked up a ladder.
• Up a ladder Sam picked. fails the test

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Another movement rule

• Identify a meaning preserving movement rule and
  illustrate it with a non-controversial example
• He ran into the room.
• It was into the room that he ran.
• Apply the movement rule to the controversial
  examples that you want to test.
• He climbed up a ladder.
• It was up a ladder that he climbed. passes the
  test
• He picked up a ladder.
• It was up a ladder that he picked. fails the
  test

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Be sure that you are testing the right thing

• Are these sentences relevant in showing Tree 1
  and Tree 2 have different structures?
• It was a ladder that Sam climbed up.
• It was a ladder that Sam picked up.
• Sam climbed up a ladder and a wall.
• Sam picked up a ladder and a rope.
• ?A ladder was climbed up by Sam.
• A ladder was picked up by Sam.
• A ladder he climbed up.
• A ladder he picked up.

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Discussion

• Test each sentence with coordination and movement
  tests for Tree 1 and Tree 2.
• I took out the garbage.
• I turned off the light.
• I turned off the highway.
• I fell off my bike.
• I looked up the number.

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Constituency of Verb Phrases
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A class participation exercise(based on Radford,
Chapter 3, exercise IX)

• Goals of the exercise
• Relying on tests when your intuition fails
• Adapting to inconsistent results
• (e.g., find evidence for disqualifying some of
  the tests)
• The five trees on the following slide have all
  been proposed by linguists, in published
  articles, for the sentence He has been writing a
  letter.
• Unlike the previous exercise with particles and
  PPs, people do not have good intuitions about
  which structure is correct.
• We will learn several more tests for
  constituency, and apply them to these sentences
  in order to pick one of the trees as the correct
  one.
• The answer comes out different every year
  (depending on grammaticality judgments and
  creativity in finding evidence for disqualifying
  some tests).

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TREE 1
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Test 3 Deletion

• A constituent can be deleted, if you can identify
  an appropriate meaning-preserving deletion rule.

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Verb Phrase Deletion

• A meaning preserving deletion rule for VP (verb
  phrases)
• John was writing a letter and Bill was writing a
  letter too.
• John was writing a letter and Bill was writing a
  letter too.
• John was writing a letter and Bill was too.
• Condition you need to leave behind an auxiliary
  verb or insert do if there was no auxiliary verb.
• John wrote a letter and Bill wrote a letter too.
• John wrote a letter and Bill did too.

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Note to myself. Feel free to read it.

• John wrote a letter and Bill too.
• Stripping, not verb phrase deletion.
• Sam likes chocolate, and vanilla too.
• Sam likes chocolate and Sam likes vanilla too.
• Looks like a non-constituent was deleted (so its
  not left-peripheral ellipsis either).
• It is still a test for constituency because the
  piece left behind has to be a constituent (I
  think).

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Test 4 Pro-Forms

• A pronoun can substitute for a noun
• Sam went to school.
• He went to school.
• Other pro-forms can substitute for other parts of
  speech.

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A Pro-VP Do so

• Put do in the same form as the verb you are
  substituting it for.
• The English verb forms are base, present, past,
  present participle, and past participle.
• John wrote a letter and Bill wrote a letter too.
• John wrote a letter and Bill did so too.
• Write and do are in the past tense.
• John was singing and Bill was singing too.
• John was singing and Bill was doing so too.
• Sing and doing are present participles.

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A meaning-preserving movement rule for VPs

• I thought he was singing and he was singing.
• I thought he was singing and singing he was
  singing.
• I thought he was singing and singing he was.
• Like Verb Phrase Deletion, this movement rule
  must leave an auxiliary verb behind. If there is
  no auxiliary verb, insert do as an auxiliary
  verb.
• I thought he would sing a song and he did sing a
  song.
• I thought he would sing a song and sing a song he
  did.

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Test 5 Adverb Placement

• Sentence Adverb
• Probably he can rely on my support.
• He probably can rely on my support.
• He can probably rely on my support.
• ?He can rely probably on my support.
• ?He can rely on my support probably.

• VP Adverb
• Completely he can rely on my support.
• He completely can rely on my support.
• He can completely rely on my support.
• He can rely completely on my support.
• He can rely on my support completely.

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Adverb placement

• Sentence adverbs must be immediately dominated by
  a node labeled S.
• VP adverbs must be immediately dominated by a
  node labeled VP.

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Non-Constituent Coordination

• John found the letter and Bill signed the letter.
• John found the letter and Bill signed the letter.

S
VP
NP
NP V Det N
John found the letter
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Non-Constituent Coordination

• I gave a book to Mary and gave a letter to Sue.
• I gave a book to Mary and gave a letter to Sue.

S
VP
NP V NP PP
I gave a book to Mary
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Right Node Raising

• If you conjoin two strings of words that have
  identical final constituents, delete the first
  instance of the identical constituent.
• John found the letter and Bill signed the letter.

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Left Peripheral Ellipsis

• If you conjoin two strings of words that have
  identical initial constituents, delete the second
  instance of the identical constituent.
• I gave a book to Mary and gave a letter to Sue.