Russian (Indo‑European, Slavonic)

Some nouns are morphologically adjectives (and can't be used as adjectives).

1 Background

Noun and adjective declension are quite distinct from each other, as seen in the paradigm below:

2 Deponency in Russian

2.1 Morphologically adjectival nouns

There are a few nouns that decline like adjectives, e.g.:

In spite of its morphology, it does not have the syntactic properies of adjectives; e.g. it cannot be used attributively:

Etyomologically, portnoj is the lexicalization of a now-obsolete adjective portnoj 'fabric' (itself derived from the now-obsolete noun portno 'fabric'), used as a noun. Following Huddleston and Pullum (2002), such formations can be called 'fused head-modifiers', i.e. a modifier with an assumed underlying noun head. These are still productive in Russian, e.g. the adjective bol´noj 'sick', can be used by itself as a noun meaning 'sick person, patient'. Note, though, that these vary in form according to the gender of the referent, like adjectives, while a noun such as portnoj has a fixed gender, like a noun. If a female referent is intended, another noun must be used (such as portnixa 'seamstress'):¹

Zaliznjak's (1987) morphological dictionary lists a number of nouns which are formally adjectives (roughly 80-90, if participles are excluded), though in many cases, adjectival uses still occur. There is an interesting subclass, consisting mostly of militaryor nautical terms, where the adjective is characterized by initial stress and the noun by end stress, such as staršój '(a) superior' (cf. stáršij 'older') or mačtovój 'mastman (cf. máčtovyj 'having to do with a mast'). In these cases the noun is formally distinct from the adjective.

Some such nouns have actually skipped the adjectival stage in Russian, their adjectival form due to their being learned formations. For example, nasekomoe 'insect' was a calque on Latin insectus (via French, according to Vasmer's Russisches etymologisches Wörterbuch), literally 'cut into', itself a calque on a Greek word. Morphologically, the Russian word is the present passive participle (following the Latin model) of nasekat´ 'cut', in the neuter form. (Similarly with the present active participle mlekopitajuščee 'mammal', a Church Slavonicism, literally meaning 'milk suckler'.) Although participles are morphologically adjectives, nasekomoe cannot typically be used as an adjective.²

In at least one respect, though, such nouns are still treated as adjectives by syntax. The numerals '2', '3' and '4', when in the nominative (or inanimate accusative), have case goverment properties which treat nouns and adjectives differently. With nouns, they select a form which is typically equivalent to the genitive singular. With adjectives, they select the genitive plural (or optionally, in the case of feminines, the nominative plural). Morphologically adjectival nouns, which are all masculine or neuter, take the genitive plural in these constructions, and so are treated like adjectives:

2.2 Mixed types

Thus, the mixed class nouns represent a unique mixture of nominal and adjectival morphology.

Notes

¹ Marginally, the feminine form portnaja may be found in artificial bureaucratic usage.

² Note though that attributive adjectives can be formed from such nouns by conversion, e.g. from životnoe 'animal', which has the form of a neuter adjective, one finds životnyj mir 'animal kingdom' (literally 'animal world')', where životnyj is a masculine adjective modifying mir 'world'.

References

Huddleston, Rodney and Geoff Pullum. 2002. The Cambridge grammar of the English language. Cambridge: Cambridge University Press.

Zaliznjak, A. A. 1987. Grammatičeskij slovar´ russkogo jazyka. Moscow: Russkij jazyk.