Morphological Productivity and the Mental Lexicon
This topic is based on two observations about morphology:
(1) a. Though many things are possible in morphology, some are more possible than others.
b. Though there are infinitely many potential words in a language, some are more likely to become actual words than others.
These two statements, while similar, express slightly different ideas. The first (1a) is a general statement about morphological processes. We have seen that morphology can take many forms. Limiting ourselves to English, regular derivation and inflection might involve affixation, internal change (ablaut and umlaut), and category change without any overt morphological marking, to name just a few. But some of these processes are more possible than others. In the realm of verb inflection, a randomly selected verb is more likely to make its past tense by affixation than by ablaut. The second statement (1b) deals specifically with individual words. On a very basic level, words such as pfug, ngu, or yawelelulitopikuro are much less likely to become actual words of English than fug, ung, or yawel. On another level, a word like mini-burger ‘little burger’ is more likely than burgerlet (and may, in fact, already exist), even though -let, like mini-, means ‘small’ (cf. booklet, piglet). More subtle differences among forms and how likely they are to become actual words can be tested only through carefully designed experiments. Issues like these fall under the rubric of morphological productivity.
