Language is a goal-directed activity. Grammaticography converts this theoretical principle into a methodological principle. This helps to get consistency in the description of dynamic phenomena.

Derivational processes

A derivational process may change the category of the base, as when a noun is derived from a verbal base. A descriptive grammar has a chapter on the noun, with a subsection on the formation of nominal stems. One process of nominalization is by transforming verbal bases into noun stems. This may be a subcase of the (overt) derivation of noun stems from verbal bases and/or of the (covert) conversion of verbs into nouns. All of such processes are dealt with in the chapter devoted to nouns or, more generally, to nominal constructions.

The above theoretical principle forbids doing it the other way round. The chapter devoted to the verb has nothing to do with their transformation into nouns.

Grammaticalization

A synchronic descriptive grammar cannot pursue the complete grammaticalization process of a given formative or construction from its source to its target. Grammaticalization converts an input construction into an output construction, which by definition are different. Consequently, they are described in different chapters of the grammar. Not only the structure, but also the function of a construction changes by grammaticalization. Therefore neither the structural nor the functional grammar can follow a complete grammaticalization process in a coherent way.

The solution is to integrate into the description of a construction a paragraph on its dynamic source or base. Some would call this a diachronic explanation of the construction. It is crucial not to do it the other way round: The chapter describing a given construction does not describe how it is grammaticalized into other constructions. Instead, this latter chapter is linked up with the other chapter by a mere cross-reference.

Some grammaticalization paths combine more than two stages, as when A is grammaticalized to B, and B is grammaticalized to C. By the principle just mentioned, the chapter devoted to B mentions its origin in A; and the chapter devoted to C mentions its origin in B. For instance, the Cabecar positional (ka-)rä is grammaticalized to the copula rä; and this is grammaticalized to a thematic structure articulator.

Often a given source lexeme or construction is grammaticalized in different directions, producing different targets. The phenomenon is known as polygrammaticalization. Again, the different targets of such a branching process each have their chapter devoted to them. Each of these chapters describes the formation of the construction out of its base. The chapter devoted to the common base cannot describe the polygrammaticalization in a cohesive way. Instead, it cross-references the chapters devoted to the targets. For instance, the Cabecar copula grammaticalizes both to a thematic structure articulator and to a clause-final validator. Both the chapter devoted to thematic structure articulation and the chapter devoted to final validation mention the origin of the formative as the copula. The chapter on the copula only cross-references the latter two chapters.