The present paper addresses the question how in syntactic parsing the coverage of words in previously unseen text may be improved. The adjectives in English are presented here as a case study. Working on the assumption that most new words that are introduced into the language are constructed on the basis of already existing words through the application of word-formation processes, we investigate the role that different word-formation processes play, more specifically in the formation of adjectives in English. An analysis of adjectives in the BNC shows that in the case of adjectives compounding is the word-formation process that is most productive. Moreover, compound adjectives are not formed by combining bases at will; rather, a limited set of fairly simple rules apply that restrict the co-occurrence of bases. This makes it feasible to develop an approach for handling compound adjectives which is rather effective, as is evident from the results from a first implementation where of a set of 30,561 compound adjectives derived from the BNC, 88.68% were correctly identified as such. Incorporation of the rules in the grammar underlying the Pelican parser accounts for a 7.65% increase in the parser's coverage of a subset of 10,123 sentences taken from the Leipzig corpus.