We do not actually have to go to other languages such as Swahili to discover that “word forms” may consist of a number of elements. We can recognize that English word forms such as talks, talker, talked and talking must consist of one element talk, and a number of other elements such as -s, -er, -ed and -ing. All these elements are described as morphemes. The definition of a morpheme is “a minimal unit of meaning or grammatical function.” Units of grammatical function include forms used to indicate past tense or plural, for example.

In the sentence The police reopened the investigation, the word reopened consists of three morphemes. One minimal unit of meaning is open, another minimal unit of meaning is re- (meaning “again”) and a minimal unit of grammatical function is -ed (indicating past tense). The word tourists also contains three morphemes. There is one Morphology 67 minimal unit of meaning tour, another minimal unit of meaning -ist (marking “person who does something”), and a minimal unit of grammatical function -s (indicating plural).