Language is a cognitive and communicative activity. It is structured in the form of language systems. The language system is a semiotic system. As such, it is the result of the interplay of two essentially independent forces:

  1. Formal constraints on structure: The constraints on a semiotic system and on the messages constructed with it are of a heterogenous nature. Laws of logic and information theory determine how signs may be selected and combined. Laws of physics determine the composition and transmission of signs. These are complemented by other laws of nature in the case of semiotic systems used by a particular species, e.g. homo sapiens.
  2. Functions of communication and cognition: The world surrounding us which we conceptualize is in many respects the same for every speech community; and the same goes for the tasks of communication in such a community. These two domains provide the total of content and its conveyance in the widest sense.

Thus, entities of grammar have a purely formal side determined by the constraints imposed on any semiotic system. At the same time, this formal side is not empty, but is laden with cognitive and communicative content. In more concrete terms: Grammatical categories, relations, constructions and operations are necessary for a semiotic system to operate, and they do have some purely formal properties. At the same time, those are categories like tense, relations like the indirect object relation, constructions like the causative construction and operations like nominalization; and none of these is purely formal, all of them have their semantic side. Putting it yet another way: in a semiotic system, everything concerning the sign as a whole is meaningful.

The double-sidedness of grammatical entities has many methodological consequences. Two are of immediate relevance here: First, definitions of a grammatical category are mixed definitions, combining semantic and structural criteria. Second, any analysis of grammatical categories aiming at understanding their nature has to take a double approach to them, a formal and a functional approach. Semasiological grammar takes the formal approach, onomasiological grammar takes the functional approach.

The functional approach to grammatical description takes the semantics of grammar as the starting point and structuring principle of the description. The highest structuring unit is the functional domain. It is assumed that the total of meanings/functions coded in the grammars of languages can be grouped in a manageable set of areas, called functional domains of language. These may be presupposed in the functional description of any language. Every language codes some of the concepts, functions and operations involved at the level of grammar, codes others in the lexicon and ignores yet others, leaving them, perhaps, to inference. The following is a set of functional domains that have proved useful in general comparative grammar and in linguistic description.

Functional domains of language
functional domainmain areas
substantive notions, denominationnominal classification, proper names, relationality (kinship), formation and modification of substantive notions
quantification, measure, orderplurality, counting, non-numeral quantification, measurement and collection
referenceindividuation, anchorage (incl. deixis), endophora (incl. reference tracking, determination)
possessionpossession in reference, possessive predication, possession and participation, past and future possession
predicationexistence and presentation, identification, categorization, characterization (property, comparison), state, change of category/property/state; secondary predication
participationactor and control (causation, actor demotion), undergoer and affectedness (applicative constructions, introversion), indirectus, desideration, experience, peripheral roles
design of situationsholistic 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)
spaceposition and posture (incl. spatial and gestalt properties of objects), motion, reference points, spatial regions, local relations
timemoment and span, absolute time, temporal relation
modalityobligation, volition, possibility; epistemic evaluation, evidentiality; validation, acceptance, regret
negationsemantic scope of negation, negation and quantification
junctionproposition vs. state-of-affairs, intrinsic relations (content propositions), extrinsic relations (logical relations, concrete relations), pragmatic level of interpropositional relations
discourse structureinformation structure (topicalization, presupposition vs. assertion, focusing), emphasis
communicative relationscommunication channel, illocution (declaration, question, request and command, hortatory/monitory), speaker's state of mind (incl exclamation); metalinguistic operations (speech reproduction, operations on the code)

German page on Funktionale Domäne