Morphology

Types of Morphemes

A morpheme is the smallest unit of grammatical or semantic meaning in a language. A morpheme is distinct from a phoneme because although a phoneme is the smallest meaningful unit of sound in a language, by itself a /p/ or /m/ does not have grammatical or semantic meaning. It must be combined with other phonemes into a morpheme to have such meaning.

When discussing morphemes, it is important not to confuse them with words, since there is a difference between the two. Consider the following words: the, boy, runs, and unlucky. Although each of these is a “word,” they are all very different in their make-up and usage. The term “word” therefore is not very precise. When we turn to the first two of these examples—the and boy—we see that it is not possible to divide them into smaller units of grammatical or semantic meaning. For example, we cannot divide boy into smaller units such as b- or –oy. In other words, boy is a single morpheme. The same is true of the.

The word runs, however, can be divided into smaller units, that is, into more than one morpheme: run and –s. Each of these has a distinct meaning, and so run and –s are each morphemes. The word unlucky can be divided into three morphemes: un-, luck, and –y. Each of these has a meaning that we know and recognize as English speakers. Here is where we see the distinction between morphemes and words. We do not consider un– or –y or –s as “words,” but they each have a distinct meaning, i.e., they are each morphemes.

The examples above reveal that there are different types of morphemes:

  • Free morphemes can stand on their own as words; they do not have to be attached to other morphemes. Examples: the, boy, run, and luck.
  • Bound morphemes cannot stand alone but must be bound to other morphemes. Examples: –s, un– and –y.

Bound morphemes are often affixes. This is a general term that comprises prefixes, which are added to the beginnings of words, like re– and un-, and suffixes, which are added to the ends of words, like –s and –ness; some languages also have infixes, which are added into the middle of words, but these are rare in English.

Bound morphemes are further divided into two subtypes:

  • Derivational morphemes change the meaning or the part of speech of a word (i.e., they are morphemes by which we “derive” a new word). An example is un-, which gives a negative meaning to the word it is added to, –y, which turns nouns into adjectives, or –ness, which turns adjectives into nouns.
  • Inflectional morphemes add grammatical information to the word, such as –s on runs, which tells us that it is 3rd person singular present tense verb, or the –s on boys, which tells us that there is more than one boy.

There are eight inflectional suffixes, or more simply inflections, in English:

  • -s on verbs: 3rd person sg, present tense (he runs, she walks)
  • -ed on verbs: past tense: (I walked, they joined)
  • -ing on verbs: progressive (I was walking; they were joining)
  • -en on verbs: past participle (I was beaten; she has eaten)
  • -s on nouns: plural (boys, books)
  • -‘s on nouns; possessive (boy’s, book’s)
  • -er on adjectives: comparative (quicker, slower)
  • -est on adjectives: superlative (quickest; slowest)

Several of these inflections are similar phonologically, but do not confuse them. The –s on the end of 3rd person singular verbs, the –s plural on nouns, and the -‘s possessive ending are the same purely by coincidence. Also, do not confuse the –ing inflectional ending used to make verbs progressive (“I am singing”) with the derivational morpheme –ing used to make verbs into nouns (“Singing is a fun thing to do”). They sound the same, but they are used differently. Finally, do not let spelling confuse you. We signify possessive plurals in spelling by adding an apostrophe to the end of the word (e.g., boys’) but the only inflectional ending here is the s-plural. The apostrophe is just a spelling convention.

There is one final distinction between different kinds of morphemes:

  • content morphemes, which have a clear semantic meaning (like book, luck, un-, –y, boy)
  • function morphemes, which include all inflectional morphemes like –s, and –ed, but also include free morphemes such as the, of, with, and, but, and words like that. These words signify the grammatical relationships between words and give structure to a sentence.

The wikipedia page on function words has an excellent example of the difference between content words and function words. Read these two sentences:

  1. The winfy prunkilmonger from the glidgement mominkled and brangified all his levensers vederously.
  2. Glop angry investigator larm blonk government harassed gerfritz infuriated sutbor pumrog listeners thoroughly.

In the first sentence, all the content words have been replaced with nonsense words, but notice how the grammatical structure of the sentence is still clear. You can tell that winfy is an adjective, that the words mominkled and brangified are past tense verbs, and so on. In the second sentence the content words are English but the function words have been replaced. This sentence is entirely incomprehensible!

Allomorphs

Allomorphs are non-meaningful variants of a morpheme. For example, the -s plural takes three distinct phonological forms in the words boys, books, and dishes. If we write the three words in IPA, [bɔɪz], [bʊks] and [dɪʃɪz], we see that the plural suffix has three forms: [s], [z], and [ɪz]. These are three non-meaningful variants, allomorphs, of the -s plural morpheme.