A fundamental requirement for a comprehensive description of a language is the

Categorical imperative of language description

Describe your language in such a way that the maxim of your description could serve, at the same time, as the maxim of the description of any other language. (Lehmann 1989, § 3)

Lehmann, Christian 1989, “Language description and general comparative grammar”. Graustein, Gottfried & Leitner, Gerhard (eds.), Reference grammars and modern linguistic theory. Tübingen: M. Niemeyer (Linguistische Arbeiten, 226); 133-162. [download ]

Since languages are both alike and diverse, this condition is janus-headed:

1. On the one hand, the description must bring out the specific characteristics of this language.
2. On the other, where all languages are alike, the description must follow a universal model.

If the two requirements are not met, the description fails both on theoretical and on practical accounts:

A description that is structured by concepts which are alien to the language does not meet requirement #1. It fails theoretically and is scientifically uninteresting. It fails practically because one cannot learn or use a language by applying a description that does not fit its structure.

A description that does not meet requirement #2 is obscure, making the language appear as something strange and incomparable to other languages. It is not usable for general-comparative linguistics and consequently does not feed into general-comparative grammar and into the construction of a theory of language.

Consequently, the descriptive linguist needs a general framework which incorporates what is universal about languages and is adaptable to the specific traits of the given language. One is proposed in the section of the comprehensive presentation of a language.