The transformation criterion

Those who view conversion in its narrower sense, as a process of word-derivation limited to the formation of verbs from nouns and nouns from verbs, use a different terminology

for other cases of transposition. Thus, the process of forming nouns from adjectives (the blind, the unemployed) is usually called substantivation.

In contrast to conversion substantivation is a gradual process: adjectives are first only partially substantivized and for a long time can be modified by an adverb like regular adjectives but not nouns (the extravagantly jealous man). Scholars also point out that in contrast to conversion subtantivation is limited to a certain class of words: human beings (the poor, the black, a creative, a criminal, a gay) and some abstract concepts (the impossible, the Present). Still another argument they give to prove that substantivation is a process different from conversion is that the former is mainly the result of ellipsis as in the elastic (cord) taking place only under certain circumstances. That is why not every adjective may be used as a noun.

Other cases involving the use of words in a different syntactic function, less frequent and less regular. One of them is called adverbialization. It takes place in a limited number of English adjectives have adverbial uses (he spoke loud/loudly) which allows to consider them adverbs derived by adverbialazation, or a functional shift/transposition/conversion.

Another case of transposition is adjectivalization - the use of nouns and participles as adjectives. There are, however, some problems in defining adjectives: English nouns are commonly used in an attributive function (a stone wall) but not all of them are adjectives yet, as in the case of home affairs. The nominal character of many premodifiers is proved by their correspondence to prepositional phrases with the noun as the compliment (a love poem 'a poem about love') that can hardly be possible for real attributive adjectives like a long poem.