Derivational Vs. Inflectional Morpheme
As discussed in class, there are two types of morpheme: FREE morpheme, and BOUND morpheme. FREE morpheme is then further divided into two: LEXICAL and FUNCTIONAL morpheme. BOUND morpheme is also further divided into two categories: DERIVATIONAL and INFLECTIONAL morpheme.
DERIVATIONAL morpheme changes the root's class of words OR its meaning, OR BOTH. The word 'unhappy' derives from the root HAPPY added with a prefix UN. Both 'happy' and 'unhappy' are adjectives. The meaning, however, is totally different. "I am unhappy" is totally different from "I am happy". In this case, the prefix UN is called DERIVATIONAL MORPHEME.
INFLECTIONAL morpheme, on the other hand, does not change either the root's class of words or the meaning. The word 'books', for example, derives from the root BOOK added with a suffix –S. Both 'book' and 'books' are NOUN. The meaning is still the same. The suffix –S only indicates the plural form. In this case, the suffix –S is INFLECTIONAL