The presupposition of the coordination test is the principle that coordination (by ‘and’ or ‘or’) is only possible for structurally independent units, i.e. syntactic rather than morphological constituents.

Let a certain grammatical obtain relation between an element O conceived as an operator and an element S conceived as being in its scope. The question in the analysis concerns the autonomy status of O, i.e. the question at which level of grammatical structure it figures. The coordination test contributes to resolving this.

1. If [ S [O1 and/or O2]] is possible, this is evidence that both units of category S and units of category O abide at a higher level of structural autonomy than if this were impossible.
2. If [[S1 and/or S2] O ] is possible, this is evidence that O can be combined with a syntactically complex construction. Then O is at a higher level of structural autonomy than if this were impossible.

Boundary cases modifying this principle are taken up below.

Let O be the French finite verb and S be a lexical nominal expression in direct object function. The question is, as before, whether [[O1 et O2] S ] is possible. f are from Zwicky 1977:5.

The test construction (b) is possible. Now let S be a clitic pronoun, as in a.

The coordination test in b fails. This not only confirms that clitic pronouns are at a lower level of structural autonomy than lexical nominal expressions. It also suggests that clitic pronouns approach the status of affixes.

Generally, parts of words cannot be deleted under coordination (Zwicky 1977:3). Thus, Engl. yellowish or greyish cannot be reduced to yellow or greyish if meaning is to be preserved. Likewise, dancing and singing cannot be reduced to dance and singing. This shows that both the derivational operator -ish and the derivational/inflectional operator -ing are typical affixes.

The test produces the same results for most German affixes, too. There are, however, a few derivational suffixes which elude it. Thus German diagnostizier- und therapierbar ‘capable of diagnosis and therapy’ is an instance of [ [ S1 und S2 ] O ] which argues that this O (viz. -bar) enjoys a higher degree of structural autonomy than other suffixes.

Again, if the coordination test is applied to the two components of a compound noun, the result is often positive. Both two stems in determinans function can be coordinated, as in Staats- und Völkerrecht ‘public and international law’; and two stems in determinatum function can be coordinated, as in Kundenberatung und -betreuung ‘customer advice and support’. Such compounds may be borderline cases between morphological and syntactic constructions.

The coordination test is an important criterion in the determination of the degree of grammaticalization of a formative O, chiefly in the function of postposition or suffix on S (Lehmann 2015, ch. 4.3.2; 2023).

References

Lehmann, Christian 2015, Thoughts on grammaticalization. 3rd edition 2015. Berlin: Language Science Press (Classics in Linguistics, 1). [ download ]

Lehmann, Christian 2023, “Postpositions in Cabecar”. Cuadernos de Lingüística de El Colegio de México 10, e268 [online ]

Zwicky, Arnold M. 1977, On clitics. Bloomington, IN: Indiana University Linguistics Club.