Phrase Structure

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Phrase Structure

• The formal means of representing constituency

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Constituents are hierarchically organized

• S
• NP VP
• D N V PP
• the man eats
• P NP
• at
• Adj N
• fancy restaurants

The man eats at fancy restaurants.
S NPDthe Nman VP Veats PP Pat NP
Adjfancy Nrestaurants
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Phrase Structure Rules

• Rules to represent hierarchical structure
• eg. S ? NP VP
• S
• NP VP

constituent
(sub)constituents
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Phrase Structure Rules

• XP ? (YP) X (ZP)

X,Y,Z are variables representing any category (eg
N, V,A, P etc)
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Phrase Structure Rules

• NP ? (D) (AP) N (PP)

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Phrase Structure Rules

• NP ? (det) (AP) N (PP)

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Noun Phrases (NP)

• A noun phrase can be just a bare noun
• NP John left (cf. NP the man left)
• So all other material other than the Noun itself
  will be optional.
• NP ? N

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Noun Phrases (NP)

• NPs can have an optional determiners and
  adjective (phrases).
• You are allowed one determiner and as many APs as
  you like
• slippers
• the slippers
• pink slippers
• the pink slippers
• pink fluffy slippers
• the pink fluffy slippers
• the a slippers

NP? (D) (AP) N
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Noun Phrases (NP)
NP? (D) (AP) N

• NP
• D AP AP N
• the slippers
• A A
• pink fluffy

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Noun Phrases (NP)

• NPs also allow as many optional PPs following the
  N as you like
• The book of poems
• The book of poems with the red cover
• The book of poems with the red cover from New York

NP? (D) (AP) N (PP)
Is this rule the final one? Not even close! (For
example, it doesnt have a means of incorporating
relative clauses). However, well start with this
as a working hypothesis.
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Adjective/Adverb Phrases (APs)

• Adjectives Adverbs can stand on their own as
  phrases
• John left quickly
• the red lipstick
• AP ? A
• But they can also be modified by other APs
• John left rather quickly
• the very red lipstick
• AP ? (AP) A

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Adjective/Adverb Phrases (APs)

• A situation easily confused
• The big yellow balloon
• The very yellow balloon
• What does big modify? What does very modify?

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The Principle of ModificationThe Golden Rule

• If one constituent modifies another then those
  two constituents are sisters. (ie. They must be
  part of the same constituent)

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Prepositional Phrases (PPs)

• These generally consist of a Preposition and an
  NP
• up the road
• on the video screen
• under the avocado
• PP?P NP

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Prepositional Phrases (PPs)

• Is the NP in a PP optional?
• I threw the garbage out
• The construction workers blew the building up
• I havent seen him before
• PP?P (NP)
• This is controversial not everyone agrees these
  are prepositions.

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Verb Phrases (VP)

• Verbs by themselves
• Marko arrived
• Susan sang
• VP? V
• Verbs can be modified by adverbs
• Marko often sang
• Susan sang beautifully
• Luis often sang beautifully
• VP ?(AP) V (AP)

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Verb Phrases (VP)

• Verbs modified by PPs
• Marko sang though a microphone
• Susan sang to her parents
• VP? (AP) V (PP) (AP)
• Verbs with an NP object
• Marko sang a song
• VP ?(AP) V (NP) (PP) (AP)
• Verbs with a Sentence Object
• Fred said Marko sang a song
• VP ?(AP) V (NP/S) (PP) (AP)

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Verb Phrases (VP)

• VP ?(AP) V (NP/S) (PP) (AP)

VP AP
V NP PP
PP A got D N P
NP P NP frequently
his buckets from D N for D N
the
store a dollar
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Clauses (Sentences)

• Sentences consist of a subject (NP) and a
  predicate (VP). In English, neither is optional
  (although in other languages the subject may be
  omitted)
• S ? NP VP

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Clauses (Sentences)

• Sentences may have an optional auxiliary or modal
  verb (of the Category T)
• S ? NP (T) VP

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Embedded Clauses

• Sometimes clauses can function as the subject or
  object of other clauses.
• I asked if Maria would eat the spaghetti
• I think that Maria decked the Janitor
• That Maria decked the Janitor is obvious
• Words like that and if are called
  complementizers.
• S'?(Comp) S

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Embedded Clauses

• VP?(AP) V (NP/S') (PP) (AP)
• S ?NP/S' (T) VP

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S
NP
VP
T
didnt
D N V
S
the syntactician think
Comp S
that
NP VP
D N V NP
the phonologist said
D N
the sentence
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Recursion

• Language is infinite you can say sentences that
  have never been said before.
• NP ? N PP
• PP ? P NP

This property is called Recursion
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Summary

• Constituency hierarchical structure is captured
  by phrase structure rules (PSRs)
• These rules also capture the recursive (infinite)
  property of language.

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PSRs of English

• S' ?(Comp) S
• S ?NP/S' (T) VP
• VP?(AP) V (NP/S') (PP) (AP)
• NP ?(D) (AP) N (PP)
• PP ? P (NP)
• AP ? (AP) A

to be significantly revised