2. Building trees: The notion of constituent
At a given level of analysis, we define as constituents of a syntactic unit those words or groups of words that function as immediate "children" of this syntactic unit. Every syntactic unit must itself be a constituent, the highest node being the sentence. In the sentence O governo Cardoso crescia com a crise, none of the nouns is a direct constituent ("child node") of the sentence. governo is part of a noun phrase (np), which IS a constituent (subject) of the sentence, while crise is placed even lower in the tree, being part of a noun phrase (np), which is part of a prepositional phrase (pp), which IS a constituent (adverbial) of the sentence.
With regard to form, constituents can be either single words (crescia), or groups (o governo Cardoso, com a crise) and clauses (que hipopótamo não come peixe), both of which are complex units. With regard to dependency relation, constituents can be heads (H) or dependents (D), which is also the minimal functional distinction, often used for in-group constituents - where the number of different functions is very restricted, and predetermined by the type of group in question.
Word constituents are form-classified according to their morphosyntactic word class. Groups are classified according to their prototypical head material, i.e. noun phrase (np), prepositional phrase (pp), adverb phrase (advp) etc. The same holds for clauses, where the leading verb is regarded as head, if there is one, - yielding the categories finite (fcl) and non-finite clauses (icl). Clauses without verbs will here be called averbal clauses (acl). Averbal clauses are headed by a subordinator.
In this book, we will be using the following word classes and group types:
Though there are 7 word classes that can head groups, there are only 4 structurally distinct group types (np, ap, pp and - if acknowledged as such - vp), when one focuses not only on prototypical head material, but also on prototypical dependent material: groups allowing adjectives or pronouns as dependents fit the wider notion of np, while groups allowing adverb dependents will be denoted as ap's. Vp's are here understood as chains of auxiliaries and a main verb, in Portuguese syntactically headed by the first verb in the chain, semantically by the main verb. If recognized, vp's replace the leading verb as head of the clause.
Like groups, clauses need at least two constituents, which can themselves be words, groups og clauses. The difference between groups and clauses is that clauses contain a constituent with verbal function (predicator) and/or a complementizer (subordinator), while groups don't.
With regard to valency., dependents can be classified as argument. or as adjuncts (clause level). and modifiers (group level). respectively, the difference being that arguments are valency bound by their head, while adjuncts and modifiers are not. Consider the following examples where arguments are in bold face, adjuncts and modifiers in italics.
(a) sem dizer nada (argument of preposition, group level)
(b) prometeram[-lhe] mais um presente (dative object, clause level)
(c) na época do Titanic, ela era muito bonita (subject complement, clause level)
(d) está falando com um cliente (complement of auxiliary, verb chain)
(e) mora numa favela (argument adverbial, clause level)
(f) o estado de Minas Gerais era muito rico [em ouro] (argument of adjective)
Note that some functions can occur both valency bound and free, as is the case for adverbials and predicatives. Cp. chapter 3.2.