8. Co-ordination

A constituent that consists of 2 or more co-ordinated constituents, is called a paratagma or, with an English expression, co-ordinated unit (cu) cu is a form category, like word, group and clause. Usually, co-ordinated constituents have the same form, i.e. 2 np's, 2 adjectives, 2 predicators etc., and are co-ordinated by 1 or more co-ordinators (CO) . Coordinator function is usually filled by co-ordinating conjunctions (conj-c: e, ou, mas), but punctuation (commas, slashes) - if allowed in the tagging scheme - can also do the job. The individual co-ordinated constituents are assigned the dummy function of conjunct (CJT) with regard to their mother constituent, the cu, and their "real" outward function is lost to the cu, which "represents" them on the next higher syntactic level. Thus, in a constituent grammar analysis of the sentence

it is not the conjuncts (in italics), that function as subjects, but the co-ordinated unit as a whole (underlined). Note that e and the comma both fulfil the same function (CO).

Not only words, but groups and clauses can be co-ordinated, too, and in principle, any combination of forms is possible:

Note that the first two conjuncts could also have been tagged as words (CJT:v-fin), not clauses, without disturbing the conjunction mechanism, since conjuncts need not share the same form.

Note that the pp de e sobre crianças does not have a simple preposition as head, but a compound unit consisting of co-ordinated prepositions. Since we have so far defined groups by prototypical head forms (and prototypical dependent functions), we must now widen this definition accordingly, providing for complex head cu's with prototypical head forms as conjuncts. In doing so we gain the notational bonus of not needing a zero constituent DP (italicized) after de only to create matching pp-conjuncts (?de crianças e sobre crianças).

Co-ordination is one of the possible causes of syntactic ambiguity. For example, postnominal adjectives may be attached before or after co-ordination, as in the following case of true ambiguity:

(a)

(b)

In (a), the nouns are co-ordinated first, and function as a complex head (H:cu) for the adjective postmodifier (DN:adj). In (b), the first noun is co-ordinated with an np that has already integrated the adjective postmodifier.

In a flat CG dependency notation (c), this ambiguity can be underspecified and expressed in one analysis:

Here, the postnominal tag (N<) points left to a nominal head, but underspecifies whether this head is a single noun (guerras), or 2 co-ordinated nouns (secas e guerras).

Semantically, co-ordinations come as con-junctions (e, nem) , dis-junctions (ou ... ou, quer ... quer, ora ... ora) and contra-junctions (mas). In the case of dis-juncting (blue), there is one additional coordinator, as a kind of "left bracket" for the cu, while con-juncting (yellow) may work even without a lexical coordinator:

Sometimes, co-ordinating conjunctions introduce a main clause:

a: E leva teu irmão!

Rather than operating with "defect" co-ordinated units, with only one conjunct, one might choose to regard e in this sentence as a clause level constituent, either as CO (coordinator) or - if we want to avoid the CO function outside cu's - as fA (adverbial):

Consider also:

b: Chovia muito, e não queríamos sair.

As a matter of fact, the function of the co-ordinating conjunctions in (a,b) closely resembles that of "conjunctional adverbs" or "conjunctional adverbial expressions" that sequentially link statements in a kind of co-ordinated nexus of continuation (apesar disso), consequence (pois, por isso, eis porque, consequentemente), concession (ainda assim, ainda mesmo, apesar disso, nada obstante, no entanto) or contrast (porém, todavia).

Thus, e in (a) can be substituted by apesar disso, while e in (b) expresses consequence and could be replaced by por isso or consequentemente. Likewise, sentence-initial mas is an analogue of the adverbial expression apesar disso.

This functional and semantic resemblance between certain conjunctions and adverbs supports a clause-level analysis of e in the above cases, as for the corresponding adverbs. Next, we must choose a function tag, CO (the natural for conjunctions) or fA (the natural for adverbs). On the one hand, using CO:adv for "conjunctional adverbs" has the advantage of preserving both "conjunctionality" (as function) and "adverbiality" (as form). On the other hand, using fA:conj-c for a clause level e that has no conjuncts to conjunct, seems useful, too - and we avoid using a paratagma level function on clause level.

Co-ordination is a way of streamlining the syntax of an utterance, since (co-ordinated) groups of constituents share their functional relation to other constituents, which therefore need not appear twice in the clause: