摘要：Morphology is the study of internal structure of words Haspelmath (2002:1). There are three problems concerning to the process of morphology that the writer has formulated to conduct this research, which are; (1) what kinds of affixes that mark the adjective class? (2) What kinds of affixes that can transpose the adjective class into other word classes? And (3) What is the most productive and the most unproductive affix in adjective class. The writer concludes that the markers of the adjective class are in-, im-, il-, ir-, dis-, un-, -er, -est, -able, -ant, -ive, -ed, -ing, -ful, -less, and -al. When the adjectives are attached to some affixes, such as en-, -en, -ify, -ize, -ity, -ist, -th, and –ly, they transpose the word class of adjectives. From the instrument of the research the most productive is affix –ly, it can be combined with 84 samples of adjectives from total numbers 100 adjectives that the writer has collected. While others are -er, -est, -ness, -ty, -en, un-, -ize, -ish, -th, -im, -in, -fy, en-, ir-, il-, and dis-, they are less productive. On the other hand, the least productive or the most unproductive affixes are ir-, il-, and dis-. Each of them only can be combined with one adjective.
