The set of affixes that make up the category of bound morphemes can also be divided into two types. One type is described in Chapter 5 in terms of the derivation of words. These are the derivational morphemes. We use these bound morphemes to make new words or to make words of a different grammatical category from the stem. For example, the addition of the derivational morpheme -ness changes the adjective good to the noun goodness. The noun care can become the adjectives careful or careless by the addition of the derivational morphemes -ful or -less. A list of derivational morphemes will include suffixes such as the -ish in foolish, -ly in quickly, and the -ment in payment. The list will also include prefixes such as re-, pre-, ex-, mis-, co-, unand many more.

The second set of bound morphemes contains what are called inflectional morphemes. These are not used to produce new words in the language, but rather to indicate aspects of the grammatical function of a word. Inflectional morphemes are used to show if a word is plural or singular, if it is past tense or not, and if it is a comparative or possessive form.

English has only eight inflectional morphemes (or “inflections”), illustrated in the following sentences.

In the first sentence, both inflections (-’s, -s) are attached to nouns, one marking possessive and the other marking plural. Note that -’s here is a possessive inflection and different from the -’s used as an abbreviation for is or has (e.g. she’s singing, it’s happened again). There are four inflections attached to verbs: -s (3rd person singular), -ing (present participle), -ed (past tense) and -en (past participle). There are two inflections attached to adjectives: -er (comparative) and -est (superlative). In English, all the inflectional morphemes are suffixes.

There is some variation in the form of these inflectional morphemes. For example, the possessive sometimes appears as -s’ (those boys’ bags) and the past participle as -ed (they have finished).