swallow. NP. Wanda. V. has. V. been. V. thrilling. NP. Otto

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Syntactic Features

• Morphology, heads, gaps, etc.

2
3 views of a context-free rule

• generation (production) S ? NP VP
• parsing (comprehension) S ? NP VP
• verification (checking) S NP VP
• Today you should keep the third, declarative
  perspective in mind.
• Each phrase has
• an interface (S) saying where it can go
• an implementation (NP VP) saying whats in it
• To let the parts of the tree coordinate more
  closely with one another, enrich the interfaces
  Sfeatures NPfeatures VPfeatures

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Examples

• Verb ? thrills
• VP? Verb NP
• S ? NP VP

A roller coaster thrills every teenager
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3 common ways to use features

• morphology of a single word
• Verbheadthrill, tensepresent, numsing,
  person3, ? thrills
• projection of features up to a bigger phrase
• VPhead?, tense?, num? ? Vhead?, tense?,
  num? NP
• provided ? is in the set TRANSITIVE-VERBS
• agreement between sister phrases
• Shead?, tense? ? NPnum?, VPhead?,
  tense?, num?

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3 Common Ways to Use Features
Verbheadthrill, tensepresent, numsing,
person3, ? thrills VPhead?, tense?, num?
? Vhead?, tense?, num? NP Shead?,
tense? ? NPnum?, VPhead?, tense?,
num?
S
(generationperspective)
VP
NP
NP
Verb
A roller coaster thrills every teenager
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3 Common Ways to Use Features
Verbheadthrill, tensepresent, numsing,
person3, ? thrills VPhead?, tense?, num?
? Vhead?, tense?, num? NP Shead?,
tense? ? NPnum?, VPhead?, tense?,
num?
S
(comprehensionperspective)
VP
NP
NP
Verb
A roller coaster thrills every teenager
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S
NP
Det The
V has
N
N plan
V been
to
V thrilling
NP Otto
V swallow
NP Wanda
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(No Transcript)
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(No Transcript)
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NPh? ? Det Nh? Nh? ? Nh? VP Nhplan
? plan
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headplan
headplan
headplan
headOtto
headthrill
NPh? ? Det Nh? Nh? ? Nh? VP Nhplan
? plan
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• Why use heads?

• Morphology (e.g.,word endings)
• Nhplan,n1 ? planNhplan,n2 ? plans
• Nhthrill,tenseprog ? thrillingNhthrill,tens
  epast ? thrilledNhgo,tensepast ? went

headplan
headplan
headplan
headOtto
headthrill
NPh? ? Det Nh? Nh? ? Nh? VP Nhplan
? plan
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• Why use heads?

• Subcategorization (i.e., transitive vs.
  intransitive)
• When is VP ? V NP ok?VPh? ? Vh? NP
  restrict to ? ? TRANSITIVE_VERBS
• When is N ? N VP ok?Nh? ? Nh? VP
  restrict to ? ? plan, plot, hope,

headplan
headplan
headplan
headOtto
headthrill
NPh? ? Det Nh? Nh? ? Nh? VP Nhplan
? plan
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• Why use heads?

• Selectional restrictions
• VPh? ? Vh? NP
• I.e., VPh? ? Vh? NPh?
• Dont fill template in all ways VPhthrill
  ? Vhthrill NPhOtto VPhthrill ?
  Vhthrill NPhplan

headplan
headplan
headplan
headOtto
headthrill
NPh? ? Det Nh? Nh? ? Nh? VP Nhplan
? plan
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Post-Processing

• You dont have to handle everything with
  features. Instead, you could compose your
  grammar with a post-processor
• Use your CFG randsent to generate some
  convenient internal version of the sentence.
• Run that sentence through a postprocessor to
  clean it up for external presentation.

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Post-Processing

• External form after post-processing
• The Buddha jumped.
• Moses jumped.
• We met Smith, 59, the chief.
• Internal form (brackets show tree structure)
• CAPS the CAPS buddha jumped .
• CAPS CAPS moses jumped .
• CAPS we met CAPS smith , 59 , , the chief
  , .
• Well see a good family of postprocessors later
  finite-state transducers.

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Post-Processing

• Features and postprocessing dont do anything
  that you cant already do with nonterminals.
• Provable for certain kinds of features and
  postprocessors. Can construct a new CFG
• So they dont increase the power of CFGs.
• But they can make your grammars simpler and
  cleaner (and easier to learn automatically?).
• Just like programming in Java instead of machine
  code cant make your computer fly but makes your
  programs simpler and cleaner and easier to write.

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Part of the English Tense System
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Tenses by Post-Processing Affix-hopping
(Chomsky)

• where
• -s denotes 3rd person singular present tense
  on following verb (by an s suffix)
• -en denotes past participle (often uses en or
  ed suffix)
• -ing denotes present participle
• Etc.

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
V been
tenseprog, headthrill

• Lets distinguish the different kinds of VP by
  tense

headOtto
tenseprog,headthrill
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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present tense (again)

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present perfect tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave

• Present perfect tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave

• Present perfect tense

not ate why?

• The yellow material makes it a perfect tense
  what effects?

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave

• Present perfect tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present tense (again)

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present progressive tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V is
VP
tenseprog,headthrill
tensepres,headbe

• Present progressive tense

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan

• Present perfect tense (again)

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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave
V been
tenseprog, headthrill
tenseperf,headbe

• Present perfect progressive tense

headOtto
tenseprog,headthrill
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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave
V been
tenseprog, headthrill
tenseperf,headbe

• Present perfect progressive tense

headOtto
tenseprog,headthrill
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S
tensepres,headthrill
NP
VP
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave
V been
tenseprog, headthrill
tenseperf,headbe

• Present perfect progressive tense

headOtto
tenseprog,headthrill
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S
cond
tensepres,headthrill
NP
VP
cond
headplan
tensepres,headthrill
The plan
V has
VP
tenseperf,headthrill
tensepres,headhave
Conditional

• Present perfect progressive tense

V been
tenseprog, headthrill
tenseperf,headbe
headOtto
tenseprog,headthrill
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• So what pattern do all progressives follow?

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• So what pattern do all progressives follow?

VP
tenseperf,headthrill
V been
tenseprog, headthrill
tenseperf,headbe
headOtto
tenseprog,headthrill
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Progressive VPtense?, head?, ? Vtense?,
stembe VPtenseprog, head?
Perfect VPtense?, head?, ? Vtense?,
stemhave VPtenseperf, head? Future
or VPtense?, head?, ? Vtense?, stemwill
conditional VPtensestem, head?
Infinitive VPtenseinf, head?, ? to
VPtensestem, head? Etc. As well as
the ordinary rules VPtense?, head?,
? Vtense?, head?, NP Vtensepast,
headhave ? had
VP
tenseperf,headthrill
V been
tenseprog, headthrill
tenseperf,headbe
headOtto
tenseprog,headthrill
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Gaps (deep grammar!)

• Pretend kiss is a pure transitive verb.
• Is the president kissed grammatical?
• If so, what type of phrase is it?
• the sandwich that
• I wonder what
• What else has

the president kissed
Sally said the president kissed e Sally consumed
the pickle with e Sally consumed e with the pickle
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Gaps

• Object gaps
• the sandwich that
• I wonder what
• What else has

the president kissed e
Sally said the president kissed e Sally consumed
the pickle with e Sally consumed e with the pickle
how could you tell the difference?

• Subject gaps
• the sandwich that
• I wonder what
• What else has

e kissed the president
Sally said e kissed the president
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Gaps

• All gaps are really the same a missing NP
• the sandwich that
• I wonder what
• What else has

the president kissed e
Sally said the president kissed e Sally consumed
the pickle with e Sally consumed e with the pickle
Phrases with missing NP XmissingNP or just
X/NP for short
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VP
CP
V wonder
whyes
NP what
S/NP
whyes
e
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VP
NP
NP the sandwich
CP
whno
CP
V wonder
whyes
Comp that
NP what
S/NP
whyes
NP he
NP he
VP/NP
V was
V kissing
NP
V kissing
NP/NP
e
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VP
VP
V believe
CP
whno
CP
V wonder
whyes
Comp that
NP what
S/NP
whyes
NP he
NP he
VP/NP
V was
V kissing
NP the sandwich
V kissing
NP/NP
e
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NP
To indicate what fills a gap, people sometimes
coindex the gap and its filler.
NP the sandwich
/NP
CP
whno
Comp that
/NP

• Each phrase has a unique index such as i.
• In some theories, coindexation is used to help
  extract a meaning from the tree.
• In other theories, it is just an aid to help you
  follow the example.

/NP
NP he
/NP
V was
V kissing
NP
/ NP
e
the moneyi I spend ei on the happinessj I hope to
buy ej which violini is this sonataj easy to play
ej on ei
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• Lots of features(tense, number, person, gaps,
  vowels, commas, wh, etc., etc....)

Help!

• Sorry, thats just how language is
• You know too much to write it down easily!