330 Dik Bakker and Anna Siewierska
example, is arguably an appropriate template for the clause level.^5 The ap-
propriate template for the actual filler of the P1 position, the subject term in
this case, turns out to be DET NOUN NOMRESTR.
MAIN CLAUSE
P1 VFIN VINFIN
TERM(SUBJECT) [IMPRF,PRES,PL,3] VERB [IMPRF, GERUND]
/are/ /growing/
DET NOUN NOMRESTR
[DEF] [PL]
/the/ /trees/ TERM
ADPOS [PROX,SG] NOUN
[POSS]
/of/ /this/ /theory/
Figure 1. Expression tree with nested templates
This process of alternating template selection and slot filling provides
us with a tree in which functional categories (the ones in bold print) and
formal categories alternate. The process bottoms out in a row of nodes with
lexical and grammatical categories, such as NOUN and ADPOS, or a clus-
ter of grammatical elements, such as [PROX, SG]. By organizing the
distribution of information in this way, we attribute a dynamic character to
the process of tree construction, in which the sequence of slot filling, and
therefore time, plays a crucial role. This makes it possible to postpone the
determination of the final form of both predicates and grammatical ele-
ments until the moment at which they are eventually expressed. Elements
that have influence on the form of elements that will be expressed before
them, e.g. because they assign case to them, have to be available in time
only in as far as their assigning (functional) aspects are concerned, not nec-