Word Class Practice

1
Word Class Practice

• Oh, boy!

2
The Hierarchical Structure of Phrases and
Sentences
3
Ambiguity and Structure

• Consider the ambiguous phrase
• stupid pet tricks
• Within the phrase, the words can be grouped in
  two possible ways
• (stupid pet) tricks, i.e., tricks performed by
  stupid pets, or
• stupid (pet tricks), i.e., pet tricks which are
  themselves stupid

4
Similarly to morphology, we can draw the phrase
with a tree

• (stupid pet) tricks
• stupid (pet tricks)

5
We see ambiguity a lot

• The old men and women left the room.
• Bill sold the invisible man's hat.
• Would you like coffee or tea?
• I saw her duck.
• I said I would see you on Tuesday.
• Students hate annoying TAs.
• Sue adores men who love women who don't smoke.
• They hit the man with a cane.
• Happily they left.

6
Its sometimes pretty funny, as in these (real)
headlines

• Crack Found on Governor's Daughter
• Prostitutes Appeal to Pope
• Teacher Strikes Idle Kids
• Juvenile Court to Try Shooting Defendant
• Kids Make Nutritious Snacks
• Local High School Dropouts Cut in Half
• Hospitals are Sued by 7 Foot Doctors

7
Our study of sentence structure will allow us to
make sense of this.

• You cant wait, can you?

8
Hierarchical Structure

• Phraseology

9
Phrase and Sentence Structure Constituency

• As we just saw, we can organize words together in
  a sentence or other phrase into natural groupings
  with coherent meaning
• (stupid pet) tricks stupid (pet tricks)
• old (men and women) (old men) and women
• These groupings are called constituents.

10
Identifying Constituents

• A constituent is a group of words with a coherent
  meaning therefore, a sentence will always be a
  constituent, as will the individual words in it.
• Identifying other constituents within a sentence
  is not always so easy. There are some tests,
  however, for distinguishing constituents from
  mere strings of words.

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We will consider the following sentence

• Many executives eat at really fancy restaurants.

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The Stand Alone Test

• If a group of words can stand alone, for example
  as an exclamation or as the answer to a question,
  they form a constituent
• Q What do many executives do?
• A Eat at really fancy restaurants.
• This is therefore a constituent
• (but not)
• Q What do many executives do?
• A Eat at.
• This is not a constituent

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The Replacement by a Pronoun Test

• If a group of words can be replaced by a single
  pronoun (or word like do) with the same
  meaning, they form a constituent.
• Many executives eat at really fancy restaurants.
• They eat at really fancy restaurants.
• Many executives is therefore a constituent.
• (but)
• Many executives eat at really fancy restaurants.
• Many executives eat at really them.
• Fancy restaurants is not a constituent.

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The Move as a Unit Test

• If a group of words can be moved around, they
  form a constituent.
• It is at really fancy restaurants that many
  executives eat.
• At really fancy restaurants is therefore a
  constituent.
• (but not)
• Many at really fancy restaurants, executives eat.
• Executives eat is not a constituent.

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Issues with Constituents

• Note that we can not say whether a given group of
  words is a constituent in general, only relative
  to a given sentence. For example, consider the
  group of words Pat and Leslie
• Pat and Leslie raised llamas.
• In this sentence, Pat and Leslie is a
  constituent.
• Robin raised Pat and Leslie adopted Chris.
• In this sentence, it is not.

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Identifying Constituents

• Worksheet

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Constituents and Hierarchy

• So, we can see that constituent structure is
  hierarchical that is, one constituent may be
  part of another.
• Many executives eat at really fancy restaurants.
• But this is pretty hard to see which brings us
  back to the tree diagrams we love so much.

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A Tree Diagram

• Note that each constituent consists of everything
  below a given node.

Many executives eat at really fancy restaurants.
many executives
eat at really fancy restaurants
at really fancy restaurants
Really fancy restaurants
really fancy
Many
executives
eat
at
really
fancy
restaurants.
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A Tree Diagram

• Note that each branching point describes a
  complete constituent.

Many
executives
eat
at
restaurants
really
fancy
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Syntactic Categories

• Note that each grouping in the tree diagram is a
  member of a large family of similar expressions.
• For example, many executives belongs to a family
  that includes some people, a few of my friends,
  gorillas and many others.
• Any member of this family can be substituted for
  many executives without affecting the
  grammaticality of the sentence

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Substitution

• Many executives eat at really fancy restaurants.
• Some people eat at really fancy restaurants.
• A few of my friends eat at really fancy
  restaurants.
• Gorillas eat at really fancy restaurants.

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Syntactic Categories and Phrase Structure Rules

• These families of expressions are called
  syntactic categories. A single such expression is
  a phrase.
• The rules for how words go together to create
  phrases and how phrases in turn go together are
  called phrase structure rules.

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Noun Phrases

• Many executives, some people, a few of my
  friends, and so on belong to the syntactic
  category Noun Phrase (NP).
• An NP is a constituent which may function as a
  subject or an object in a sentence.
• You can test an NP by inserting the constituent
  into one of three contexts
• Who found _____?
• _____ was seen by everyone.
• What/Who I heard was _____.

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Noun Phrase Recognition

• Which of the following are NPs?
• a bird
• the red banjo
• have a nice day
• with a balloon
• the woman who was laughing
• it
• John
• went

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Verb Phrases

• Eat at really fancy restaurants, live in
  expensive apartments, like cheese and so on
  belong to the syntactic category Verb Phrase
  (VP).
• A VP is a constituent which may function as the
  predicate of a sentence.
• You can test a VP by inserting the constituent
  into the following context
• The child _____.

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Verb Phrase Recognition

• Which of the following are VPs?
• saw a clown
• a bird
• slept
• smart
• ate the cake
• found the cake in the cupboard
• realized that the earth was round

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Other Syntactic Categories

• A Sentence (S) consists of an NP and a VP.
• A Prepositional Phrase (PP) consists of a
  preposition plus an NP.
• An Adjectival Phrase (AdjP) consists of an
  adjective and any adverbs that modify it.
• An Adverbial Phrase (AdvP) consists of an adverb
  and any other adverbs that modify it.
• Lexical Categories (Noun, Verb, Preposition,
  Adjective and Adverb, which we examined
  yesterday) also function as Syntactic Categories.

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Phrase Structure Trees and Rules

• By labeling each constituent of a sentence, from
  individual words to groups of words to groups of
  groups, we can draw a phrase structure tree for
  it.
• Here is an example tree for a simple sentence,
  The man bought some cheese.

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S
NP
VP
D
N
V
NP
D
N
The
man
bought
some
cheese
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Phrase Structure Trees show us

• The linear order of words in a sentence, and how
  this is derived from the hierarchical structure
  of the sentence as a whole.
• The identification of the syntactic categories of
  the words and constituents in the sentence.
• The hierarchical structure of the syntactic
  categories.