Adjectivalization is the derivation of adjectives from a verb, a noun, an adjective, and occasionally from other parts of speech or from phrases. Cross-linguistically, adjectivalization seems to be less frequent than nominalization and verbalization. In most languages adjectivalization involves suffixation, but other adjectivalization devices, such as prefixation, reduplication or zero derivation, are also attested. Adjectivalization by means of suffixation has been studied in depth for English. As for other languages in which suffixation is used for adjectivalization, topics that have been studied for English are the types of suffixes used for adjectivalization, their productivity, their semantic contribution, the category of the base to which they attach, and their etymology. For English an etymological distinction between native suffixes and suffixes with a Romance, more specifically Latinate, origin can be made, related to their bound or non-bound character, the type of base to which they attach, and the prosody of the derived word. One of the major challenges to the idea of word-class changing derivation, in this case adjectivalization, comes from polyfunctional words. Participles may function both as verbs and as adjectives, which leads to the question how these complex forms are formally and semantically related. There are also derivational suffixes that are used for the formation of both adjectives and nouns. For these cases as well the formal and semantic relation has to be established. For several Western European languages a relation has been established, in the theoretical literature, between the polyfunctionality of adjectival/nominal suffixes and their influence on the prosody or the phonological properties of the root, due to their etymology. It seems that the dichotomy between two types of suffixes that is created in this way does not always occur and that there is also a mixed case.