Morphemes
A major way in which morphologists investigate words, their internal structure, and how they are formed is through the identification and study of morphemes, often defined as the smallest linguistic pieces with a grammatical function. This definition is not meant to include all morphemes, but it is the usual one and a good starting point. A morpheme may consist of a word, such as hand, or a meaningful piece of a word, such as the -ed of looked, that cannot be divided into smaller meaningful parts. Another way in which morphemes have been defined is as a pairing between sound and meaning. We have purposely chosen not to use this definition. Some morphemes have no concrete form or no continuous form, as we will see, and some do not have meanings in the conventional sense of the term.
You may also run across the term morph. The term ‘morph’ is sometimes used to refer specifically to the phonological realization of a morpheme. For example, the English past tense morpheme that we spell -ed has various morphs. It is realized as [t] after the voiceless [p] of jump (cf. jumped), as [d] after the voiced [l] of repel (cf. repelled), and as [əd] after the voiceless [t] of root or the voiced [d] of wed (cf. rooted and wedded). We can also call these morphs allomorphs or variants. The appearance of one morph over another in this case is determined by voicing and the place of articulation of the final consonant of the verb stem.
Now consider the word reconsideration. We can break it into three morphemes: re-, consider, and -ation. Consider is called the stem. A stem is a base unit to which another morphological piece is attached. The stem can be simple, made up of only one part, or complex, itself made up of more than one piece. Here it is best to consider consider a simple stem. Although it consists historically of more than one part, most present-day speakers would treat it as an unanalyzable form. We could also call consider the root. A root is like a stem in constituting the core of the word to which other pieces attach, but the term refers only to morphologically simple units. For example, disagree is the stem of disagreement, because it is the base to which -ment attaches, but agree is the root. Taking disagree now, agree is both the stem to which dis- attaches and the root of the entire word.
Returning now to reconsideration, re- and -ation are both affixes, which means that they are attached to the stem. Affixes like re- that go before the stem are prefixes, and those like -ation that go after are suffixes.
Some readers may wonder why we have not broken -ation down further into two pieces, -ate and -ion, which function independently elsewhere. In this particular word they do not do so (cf. *reconsiderate), and hence we treat -ation as a single morpheme.
It is important to take seriously the idea that the grammatical function of a morpheme, which may include its meaning, must be constant. Consider the English words lovely and quickly. They both end with the suffix -ly. But is it the same in both words? No – when we add -ly to the adjective quick, we create an adverb that is often synonymous with “rapidly”: The students quickly assimilated the concept. When we add -ly to the noun love, we create an adjective: What a lovely day! What on the surface appears to be a single morpheme turns out to be two. One attaches to adjectives and creates adverbs; the other attaches to nouns and creates adjectives.
There are two other sorts of affixes that you will encounter, infixes and circumfixes. Both are classic challenges to the notion of morpheme. Infixes are segmental strings that do not attach to the front or back of a word, but rather somewhere in the middle. The Tagalog infix -um- is illustrated below (McCarthy and Prince 1993: 101–5; French 1988). It creates an agent from a verb stem and appears before the first vowel of the word:
(1) Root -um-
/sulat/ /s-um-ulat/ ‘one who wrote’
/gradwet/ /gr-um-adwet/ ‘one who graduated’
The existence of infixes challenges the traditional notion of a morpheme as an indivisible unit. We want to call the stem sulat ‘write’ a morpheme, and yet the infix -um- breaks it up. This seems to be a property of -um- rather than sulat. Our definition of morphemes as the smallest linguistic pieces with a grammatical function survives this challenge.
Circumfixes are affixes that come in two parts. One attaches to the front of the word and the other to the back. Circumfixes are controversial because it is possible to analyze them as consisting of a prefix and a suffix that apply to a stem simultaneously. One example is Indonesian ke … -an. It applies to the stem besar ‘big’ to form a noun ke-besar-an meaning ‘bigness, greatness’ (MacDonald 1976: 63; Beard 1998: 62). Like infixes, the existence of circumfixes challenges the traditional notion of morpheme (but not the definition used here) because they involve discontinuity.
We will not go any more deeply here into classical problems with morphemes, but the reader who would like to know more might consult Anderson (1992: 51–6).
