Classes of Morphemes: Prefix, Suffix, Infix, and Circumfix
So far in our section on morphology, we have introduced the linguistic concept of the morpheme and we have discussed the categorical juxtaposition of bound and free morphemes; however, we only loosely touched upon the probably most common method of forming words: affixation. In order to discuss the methods of affixation, we have to take a look at what affixes are in the first place.
un-, -less, re-, de- mis- -ish -ing -al pre- -ism -er -s -ful -ly -ed
As you can see from the list provided, affixes are, by definition, bound morphemes. Accordingly, an affix is a morpheme that only occurs when attached to free morphemes which are then called the base, stem or root. An affix cannot stand alone.
Scanning the list of randomly chosen affixes available in the English language, you might realize that affixes can be attached before the base or after the base. Taking for instance, the root "happy" as our base, we can easily form a new lexical item by adding “un-” to form “unhappy” or “-ly” to transform the adjective into the adverb “happily”.
A prefix describes any affix that is attached in front of the root, e.g. "un-", "de-". An affix that is appended after the root is a suffix, e.g. "-ness", "-ly", "-able".
There is a third type of affix that can rarely be found in the English language but is fairly common in Semitic languages such as Arabic and Hebrew. This third type of affix is called infix: and describes an affix which is incorporated inside another word. Take for instance the nouns speedometer or decumbent. Here, the infixes -o and -m are inserted into the middle. While the latter infix is a good example for a frozen historical relic from Latin, there are also a few infixations in contemporary English -- in particular in colloquial, explicit English, e.g. abso-bloomin-lutely or guaran-friggin-tee.
A fourth and equally rare affix in the English language is the circumfix. Sometimes also termed discontinuous morphemes, the circumfix is attached to a root morpheme both initially and finally.