LET English Practice Exam

The primary function of a derivational morpheme is to create new words with new meanings. Derivational morphemes are affixes that, when added to a base or root word, change its meaning and often its part of speech. For instance, adding the prefix "un-" to the word "happy" transforms it into "unhappy," which conveys a different meaning. Similarly, the suffix "-ness" can be attached to "happy" to form "happiness," thereby creating a new noun.

This transformation allows for the expansion of vocabulary in a language, enabling speakers to express nuanced ideas and concepts. This separate yet related aspect of language development illustrates how derivational morphemes play a crucial role in enriching the lexicon. In contrast, the other options relate to functions that do not align with the primary purpose of derivational morphemes.