Unification grammar

Trying to solve the same problems

Transformational Grammar has PSRs

Transformational Grammars ALSO
need MOVEMENT

Structure-sharing MEANS unification

And VERY complicated information IN
words!

Head-driven Phrase Structure
Grammar

HPSG is the most popular Unification
Grammar

Sign-Based Construction Grammar

PHON is phonological or sound-related
information

Unless they’re PHONologists!

SYNSEM is the syntactic and semantic
information

• She
• CASE
• Nom
• We
• CASE
• Nom

• You
• CASE
• No case
• You saw me
• I saw you

• Me
• CASE
• Acc
• Accusative case
• Must be an object (complement)
• Object and complement is the same thing

• Them
• CASE
• Acc
• We saw them (good)
• Them saw him (no good)
• Saw wants an Acc complement

VALENCE features
• Also called SUBCATEGORIZATION
• SUBCAT
• SUBJ
• COMPS
• COMPS is just an object

Valence is what you want to attract

Bonding
• You are looking for a boyfriend or girlfriend
• But he/she must have a good job
• Must make more than ¥10,000,000 a year
• Must be a sports player
• Must be good at using computers
• Must not be the oldest child in his/her family
• Otherwise, you cannot bond
• Good luck

Or maybe you want a pet
• Must not be a fish
• Must not make any mess
• Doesn’t cost very much to buy
• Must be very cute
• Must understand what you’re thinking
• Must understand Japanese commands
• Otherwise, you cannot bond
• Good luck

Pochi
• A smelly dog
• Makes a lot of mess
• Not at all cute
• Doesn’t understand anything
• You are not compatible with Pochi

Language works a tiny bit differently
• A smelly dog
• Not at all cute

But generally the same
• A smelly dog
• Not at all cute

How about language?
• I saw you
• That’s OK
• Saw
• COMPS
• <NP[acc]>
• You
• CASE
• x

She
• CASE
• Nominative
• [nom]
• Nominative case
• What does that mean?
• It just means it’s a subject
• She punched Taro (good)
• Taro punched she (no good)

What about “I saw he”?
• HE
• CATEGORY
• NP
• PERSON
• 3rd
• NUMBER
• singular

• HE
• PERSON
• 3rd
• NUMBER
• Singular
• GENDER
• Male

• HE
• GENDER
• Male
• CASE
• Nominative
• Nom
• Nominative – because it must be a subject

“Saw he” – what’s the problem?

It will never work out between us

Saw us
• SAW
• COMPS <
• NP[acc]>
• US
• CATEGORY
• NP

Saw us
• Us
• CASE
• Accusative
• PERSON
• 2nd
• NUMBER
• Plural

Saw US
• Us
• Gender
• x

Saw doesn’t care about PERSON,
NUMBER, or GENDER

And they lived happily ever after

saw
• SAW
• CATEGORY
• VERB
• COMPS
• NP
• CASE
• Acc

saw
• SAW
• COMPS
• NP
• PERSON
• X
• NUMBER
• X
• GENDER
• x

John
• CATEGORY
• NP
• CASE
• X
• John can be a subject or an object
(complement)

John
• PERSON
• 3rd
• NUMBER
• singular
• GENDER
• male

SAW really wants an [acc] complement

SAW doesn’t care about anything else

John really wants to be 3rd, singular,
male

But John doesn’t care about CASE

What a wonderful sharing
relationship!

Bad sentences
• They saw we
• We is nominative [nom] case
• saw
• SUBJ< NP[nom]>
• COMPS<NP[acc]>

We walks
• Walks
• SUBJ<NP[nom]
PERSON 3rd
NUMBER singular
GENDER >
Walks wants a 3rd person singular subject with
Nominative case

We walks
• Walks
• SUBJ<NP[nom]
PERSON 3rd
NUMBER singular
GENDER >
• We is no good because it is 1st person plural.

CAT carries the syntactic features

She is a HEAD and a noun (noun
phrase)

CONTENT and CONTEXT is the
semantic info

[She] CONTENT
• PER 3rd
• NUM sing
• GEND fem

How about walks?
[walks][walks]

HEAD attribute is verb
[walks][walks]

[walks] has VALENCE attributes
[walks][walks]

VALENCE is also known as SUBCAT
[walks][walks]

VALENCE/SUBCAT who cares?
[walks][walks]

VALENCE sounds more scientific
[walks][walks]

VALENCE means attract or repel
[walks][walks]

[walks] attracts a noun
[walks][walks]

[walks] attracts a subject
[walks][walks]

[walks] specifies information about the
subject
[walks][walks]

[walks] specifies information about
CATEGORY and CONTENT
[walks][walks]

[walks]
SUBJ<CAT|HEAD noun|CASE nominative
CONT [1] | PER 3rd
NUM sing
GEND >
CONT|walker
[1]

CONT of subject matches in CONT of
the verb
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

If the verb takes [she] as a subject …
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

CONT [1] matches CONT of [she]
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

If the verb takes [she] as a subject
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

Don’t worry about the details
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

It’s all the same matching
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

Structure sharing
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

Feature sharing
CONT [1]|PER 3rd
NUM sing
GEND >
CONT|walker
[1]

So when [walks] takes [she] …
CONT [1]|PER 3rd
NUM sing
GEND x
CONT|walker
[1]

This …
CONT [1]|PER 3rd
NUM sing
GEND x
CONT|walker
[1]

… becomes this
CONT [1]|PER 3rd
NUM sing
GEND fem
CONT|walker
[1]

[walks] VALENCE features and CONT
features

Usually marked with a number in a
square

Why is it a number in a square?

Or a funny shape – it doesn’t matter

If it really happens in our brains …

The number in the square shows the
structure-sharing

That’s it!
STRUCTURE A = [m _ t _ h]
STRUCTURE B = [_ a _ c _]
Unify A and B
What happens?
A+B = [match]
That’s it!

It looks complicated
STRUCTURE A = [s _ a _ e]
STRUCTURE B = [_ h _ r _]
Unify A and B
What happens?
A+B = [share]
But it’s basically very simple (and no movement)

Here’s some [walks] info again!

Notice the VALENCE specifications

[Walks] attracts a NP with nominative
case

Walks attracts a NP with CONT
[3rd,sing]

No problem
• She walks
• That’s a good sentence
• What about this?
• Her walks
• Is that a good sentence?
• No
• Why?

[her] is CASE acc (accusative)

But it is the wrong syntactic CATEGORY

So don’t panic …
[walks][walks]

… when you see these complicated
AVMs
[walks][walks]

It takes a bit of time …
[walks][walks]

You have to get used to it
[walks][walks]

But it’s basically very simple
[walks][walks]

And no movement
[walks][walks]

Don’t forget -- VALENCE features
[walks][walks]

VALENCE or SUBCAT
[walks][walks]

1. What’s important to you?
• I don’t know
• Must be good at cooking
• Must be rich
• Whatever

2. Unification grammars do not have …
• Movement
• Movement operations

3. Unification Grammars rely on
feature ….
• Sharing
• Matching
• You could also say structure sharing

4. An attribute Value Matrix is a ….
• Model
• A model of a word or phrase

Attribute Value Matrix
[walks][walks]

5. We
• CAT
• Noun, NP
• CASE
• Nominative, [nom], nom
• PERSON
• 1st
• NUMBER
• Plural
• GENDER
• x

6. US
• CAT
• NP
• CASE
• Accusative, [acc], acc
• PERSON
• 1st
• NUMBER
• Plural
• GENDER
• x

JOHN
• CAT NP
• CASE
• x
• PERSON
• 3rd
• NUMBER
• Singular
• GENDER
• Male

8. Walks
• CAT
• Verb
• SUBJ
• NP case [nom],
• CONT
• 3rd
• Singular

9. ATE
• SUBJ
• NP
• Case [nom]
• CONT x x
• COMPS
• NP
• Case [acc]
• CONT x x

GIVES
• CAT verb
• SUBJ
• NP case [nom]
• CONT 3rd Singular

GIVES
• COMPS
• NP case [acc]
• CONT x, x
• NP case [acc]
• CONT x, x

CONTENT of gives
• CONTENT give
• GIVER 1
• GIVEN 2
• GIFT 3

GIVES (Alternative)
• CAT
• Verb
• SUBJ
• NP case [nom]
• COMPS
• NP case [acc] CONT x, x
• PP case [dative] CONT x, x
• PP = to NP

Unification grammar

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Unification grammar