The basic vocabulary of a language is the core of its lexicon. It comprises those words that are most useful for the speaker and hearer because they
- are most frequent in texts of different genres,
- designate concepts that are central to human life,
- suffice to paraphrase and explain all the other words of the lexicon.
The size of the basic vocabulary cannot be empirically ascertained; it depends on the purpose that it serves. Two variants of the Swadesh list (see below) comprise 100 and 207 items; Basic English comprises 850 items. Contrast this with the size of a complete dictionary, which may comprise any number of entries between 40.000 for Latin and 500.000 for contemporary English.
The basic vocabulary has a variety of applications in linguistics:
- In theoretical semantics, it may be used to construct a set of semantic primitives which suffice to represent all the possible meanings of a language (cf. Goddard 2001).
- In lexicography, it may suffice to define the meanings of all the other dictionary entries.
- In language learning and teaching, it may provide the basis of the vocabulary to be learnt.
- In language description, it may help the field worker to guarantee completeness at least at the lowest level.
- In language comparison, it may represent the core of the lexicon of a language.
The criteria for selecting the basic vocabulary are of two different kinds:
- Quantitative criteria: The items are the most frequent ones by certain standards. Moreover, their dispersion (distribution over styles, registers, genres etc.) is rather equal.
- Semantic criteria: The items represent central lexical fields like designations of persons and important animals, color terms, kin terms, body part terms etc.; and within each of these fields, the most basic lexemes, in terms of lexical field structure, are chosen.
These two criteria may easily be in conflict. They may then be combined as follows:
- A measure is defined that combines frequency with dispersion (e.g. by multiplying probability with dispersion). Then a list of the
n most basic items of the language by this measure is formed.
- These
n primary items are assigned to lexical fields.
- Within each lexical field, the immediate counterparts and complements to the primary items in terms of lexical relations are added to the list, so that a basic vocabulary of roughly the size of 1.5 n is produced.
For each given language, the basic vocabulary is simply a designated subset of the lexicon. Technically speaking, those lexical entries that belong to the basic vocabulary may be marked on a Boolean variable in a special field of the lexical database. The basic vocabulary may then be extracted as a word list, a glossary with translations into the background language or as a learner's dictionary.
The following basic vocabularies may be singled out as examples:
- In 1930, Charles Ogden devised his Basic English, whose vocabulary comprised 850 items. It was destined as an international lingua franca.
- In the middle of the 20th cent., Morris Swadesh devised a list of 100 basic concepts and another list of 207 basic concepts, which were translated into a large number of languages. The aim was to render lexical comparison of those languages possible, with sometimes far-reaching conclusions about their genetic affiliation. S. Lees 1953 and Glottochronologie.
- In Shin 1995, some existent basic vocabularies are compared with the aim of compiling a list that would serve in the lexicography of little-described languages.
Bibliographical references
Goddard, Cliff 2001, "Lexico-semantic universals: A critical overview." Linguistic Typology 5:1-65.
Guryceva, M.S. & Serebrennikov, B.A. 1953, "Zadači izučenija osnovnogo slovarnogo fonda jazyka." Voprosy Jazykoznanija 2(6):3-20.
Kühn, Peter 1979, Der Grundwortschatz. Bestimmung und Systematisierung. Tübingen: M. Niemeyer (Germanistische Linguistik).
Lees, Robert B. 1953, "The basis of glottochronology." Language 29:113-127.
Ogden, Charles K. 1930, Basic English. A general introduction with rules and grammar. London: Paul Treber (2nd impr. 1940).
Cf.: http://ogden.basic-english.org/basiceng.html
Shin, Yong-Min 1995, LDS Basic vocabulary. Bielefeld: AVG-Projekt (Allgemein-Vergleichende Grammatik). 
