Syntactic Theory

An Example for a Syntactic Analysis

The following sentence illustrates all grammar rules and the relevant general principles (Head Feature Principle, Valence Principle, and Specifier-Head Agreement Constraint).

Pat faxed Kim the letter yesterday.

The constituent structure of the example sentence

This sentence has the following constituent structure:

The tree already indicates which grammar rules have been applied:

• The verb faxed combines with two NPs by the Head-Complement Rule,
• The modifier yesterday is added by the Head-Modifier Rule.
• The resulting VP is combined with the subject using the Head-Specifier Rule.

Let us go through the individual local trees next.

The lower VP

The lower VP contains the verb faxed together with its two complement NPs.

The tree diagram shows the structure of the sentence, enriched with the HPSG descriptions of the nodes in the lower VP.

• The feature specifications on the words faxed and Kim follow from the lexical specification.

• The feature specification on the NP the letter follows from its internal structure. We will ignore it for the purpose of this example.

• The feature specification on the VP follows from the grammar rule and the general principles. Let's see how:
  • The Head Feature Principle:
    The HEAD value of the mother is identical to the HEAD value of the head daughter (given by the tag [a] in our example).
  • The Head-Complement Rule:
    The nonhead daughters are identical with the elements on the COMPS list of the head daughter (given by the tags [2] and [3] in our example).
  • The Valence Principle:
    Since the Head-Complement Rule only discards elements from the COMPS list of the head daughter, the other valence values are identical on the mother and the head daughter. In our example: The SPR value ([A]) and the MOD value ([B]) are shared between mother and head daughter.

The upper VP

The upper VP contains the combination of the verb phrase faxed Kim the letter with the modifier yesterday.

The following tree diagram shows the structure of the sentence, enriched with the HPSG descriptions of the nodes in the upper VP.

• The feature specification on the word yesterday follows from the lexical specification.

• We saw above how the feature specification on the lower VP faxed Kim the letter follows from its internal structure.

• The feature specification on the upper VP follows from the grammar rule and the general principles. Let's see how:
  • The Head Feature Principle:
    The HEAD value of the mother is identical to the HEAD value of the head daughter (given by the tag [a] in our example).
  • The Head-Modifier Rule:
    The head daughter is identical to the element on the MOD list of the nonhead daughter (given by the tag [4] in our example).
  • The Valence Principle:
    Since the Head-Modifier Rule only discards elements from the MOD list of the nonhead daughter, the all valence values are identical on the mother and the head daughter. In our example: The SPR value ([A]), the COMPS value ([C]), and the MOD value ([B]) are shared between mother and head daughter.

The S node