Transcript
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!!