Subcategorization Frames

Elementary trees for non-auxiliary verbs are used to represent the linguistic notion of subcategorization frames. The anchor of the elementary tree subcategorizes for the other elements that appear in the tree, forming a clausal or sentential structure. Tree families group together trees belonging to the same subcategorization frame. Consider the following uses of the verb buy:

(0)0(0

(1)

Srini bought a book.  (1)0(1

(2)

Srini bought Beth a book. 

In sentence ((1)), the verb buy subcategorizes for a direct object NP. The elementary tree anchored by buy is shown in Figure 4.1(a) and includes nodes for the NP complement of buy and for the NP subject. In addition to this declarative tree structure, the tree family also contains the trees that would be related to each other transformationally in a movement based approach, i.e passivization, imperatives, wh-questions, relative clauses, and so forth. Sentence ((2)) shows that buy also subcategorizes for a double NP object. This means that buy also selects the double NP object subcategorization frame, or tree family, with its own set of transformationally related sentence structures. Figure 4.1(b) shows the declarative structure for this set of sentence structures.

  

Figure 4.1: Different subcategorization frames for the verb buy

(a)		(b)