The set of meanings which are conveyed by grammatical formatives in languages may be subsumed under the two major functions of human language, which are cognition and communication. This may be visualized in the following diagram.
Two functions of human language
Consequently, the structure of every language supports these two main goals of linguistic activity. If operations and concepts of the areas of cognition and communication are grammaticalized, and as long as they are not yet fully grammaticalized, these two highest functions are represented in their meanings and functions.
This has led to a framework which counts with a set of functional domains of language subordinate to the two major functions of cognition and communication. These functional domains comprise all grammatical categories and operations known in typology. The following list presents a survey of them:
| functional domain | main areas |
|---|---|
| substantive notions, denomination | nominal classification, proper names, relationality (kinship), formation and modification of substantive notions |
| quantification, measure, order | plurality, counting, non-numeral quantification, measurement and collection |
| reference | individuation, anchorage (incl. deixis), endophora (incl. reference tracking, determination) |
| possession | possession in reference, possessive predication, possession and participation, past and future possession |
| predication | existence and presentation, identification, categorization, characterization (property, comparison), state, change of category/property/state; secondary predication |
| participation | actor and control (causation, actor demotion), undergoer and affectedness (applicative constructions, introversion), indirectus, desideration, experience, peripheral roles |
| design of situations | holistic vs. analytic representation (ideophones, verb series), temporal design of situations (time stability, telicity, phases of a situation), quality and quantity of situation core (manner, intensification, gradation) |
| space | position and posture (incl. spatial and gestalt properties of objects), motion, reference points, spatial regions, local relations |
| time | moment and span, absolute time, temporal relation |
| modality | obligation, volition, possibility; epistemic evaluation, evidentiality; validation, acceptance, regret |
| negation | semantic scope of negation, negation and quantification |
| junction | proposition vs. state-of-affairs, intrinsic relations (content propositions), extrinsic relations (logical relations, concrete relations), pragmatic level of interpropositional relations |
| discourse structure | information structure (topicalization, presupposition vs. assertion, focusing), emphasis |
| communicative relations | communication channel, illocution (declaration, question, request and command, hortatory/monitory), speaker's state of mind (incl exclamation); metalinguistic operations (speech reproduction, operations on the code) |
Grammaticalization paths are located in these domains. The entire topical area cannot be expanded here; the following comments must suffice:
- Some of these domains, e.g. substantive notions and denomination, possession and participation, are neatly subordinate to cognition. Others, e.g. reference, discourse structure and communicative relations, are neatly subordinate to communication. In others, e.g. polarity and modality, the two major functions of language are inextricably interwoven.
- An utterance, and often even a part of it, fulfills different functions at the same time. Grammatical units may fulfill different functions at the same time or be polyfunctional, playing thus in different functional domains. Consequently, there is overlap between the functional domains listed. The conceptual relationships among them are certainly more complex than may be represented by a list.
- By the same token, grammaticalization paths may abide inside a functional domain, but may also cross-cut their borders (which are actually inexistent).
- Most grammatical phenomena reported from newly described languages can be straightforwardly accommodated in this framework. However, it is a product of combined deductive and inductive reasoning. To the extent that it is an empirical hypothesis, it will have to be modified by future work.
- If the framework is duly detailed, it excludes most of those notions which are commonly coded in the lexicon of languages. It does not exclude all of them because it determines nothing about the degree of grammaticality with which a given category or operation is represented in a language. The example of the conventionalization of request and thanks treated in a following section illustrates the role played by the lexicon in a functional domain.
- Grammaticalization research has occasionally prompted claims about particular notions which will never be indicated by a grammatical category in any language. Such claims are, in principle, falsifiable and therefore possibly useful empirical hypotheses. However, this is not the same as claiming that a certain notion can never be grammaticalized. Such claims are not tenable in principle because any lexical item can undergo semantic change leading in the direction of a grammaticalizable notion. For instance, the claim that the notion ‘cook’ does not serve as the value of a grammatical category in any language is not equivalent to the claim that it cannot be grammaticalized. It need only be desemanticized to mean ‘make’, and the next step could be an operator of causativization.