Psrug

Phrase structure rules in Unification Grammar

Unification Grammar

• Also have Phrase Structure Rules• PSRs PLUS unification• Unification and feature structure sharing is the

same thing

• PSRs PLUS unification• No movement

Phrase Structure Rules

What’s this?

It’s simple

Mother phrases have daughters

The mother and the HEAD daughter share the HEAD feature

So in a sentence like [she walks] …

The phrase is a verb phrase

And if the non-head daughter …

(in [she walks] the non-head daughter is [she])

If the non-head daughter matches the VALENCE feature on the head daughter …

Delete the valence feature on the mother phrase

And in a mother phrase …

CONT value is the same as head daughter

[she walks]

CONT of the sentence is the same as the CONT of the verb

Here’s the CONT of [walks] if it takes [she] as a subject

It says some individual is a walker!

That individual is 3rd, sing, female

And that CONTENT is structure shared with the sentence CONTENT

Because of a simple rule

Notice the features match through the HEAD

Because it’s Head-driven phrase structure grammar

VALENCE (SUBCAT) is the exception

But that’s natural

Let’s look at some more VALENCE

VALENCE = SUBCATEGORIZATION

[sees] takes a nominative NP subject

[sees] takes a CONT [3rd, sing] subject

Complements are in COMPS

[sees] doesn’t specify CONT of the complement

Notice the CONT of the subject and complement (object) …

… structure-shared in CONT of the verb

[She saw him] is OK

[him saw she] is no good

[she saw her] – what about the CONT of the verb?

Look at CONT of [she]

CONT of [her]

Here’s [sees] again

Look at its CONT

The SEER in CONT will be …?

The CONT of [she]

And the SEEN in CONT of [sees] …?

Matched with CONT of [her]

What will all this look like?

Like this

This information …

Is enriched to this …

… by unification

How about [he sees her]?

[he sees her] subject is male

Not much difference

How about [he sees us]?

[her] is 3rd, sing, fem

[us] is 1st, plural

Not specified for gender

Exciting?

Of course it is!!