The difference between derivational and inflectional morphemes is worth emphasizing. An inflectional morpheme never changes the grammatical category of a word. For example, both old and older are adjectives. The -er inflection here (from Old English -ra) simply creates a different version of the adjective. However, a derivational morpheme can change the grammatical category of a word. The verb teach becomes the noun teacher if we add the derivational morpheme -er (from Old English -ere). So, the suffix -er in Modern English can be an inflectional morpheme as part of an adjective and also a distinct derivational morpheme as part of a noun. Just because they look the same (-er) doesn’t mean they do the same kind of work.

Whenever there is a derivational suffix and an inflectional suffix attached to the same word, they always appear in that order. First the derivational (-er) is attached to teach, then the inflectional (-s) is added to produce teachers.

Armed with all these terms for different types of morphemes, we can now take most sentences of English apart and list all the “elements.” For example, in the sentence The child’s wildness shocked the teachers, we can identify eleven morphemes.

A useful way to remember all these different types of morphemes is in the following chart.