What is a Morpheme in Morphology?

A morpheme is the minimal grammatical unit within a language. A morpheme is different from a word because a morpheme may or may not stand alone, whereas a word, by definition, is freestanding meaningful unit. Sometime a morpheme stands by itself and has a meaning of its own, it is considered a root. Example of standing alone morpheme is ‘sun’.

 Every word comprises one or more morphemes. A standalone morpheme and a word are identical but when a root word becomes modify with addition of affixes, it becomes word only.

Look at the examples:

Walk. Walker, walked, walking

The root is walk is stand alone morpheme and a word at a same time.  When root word was modifies with affixes like -s, -er, -ed and –ing it became a word consisting of two morpheme in each word.

There are two main types of morphemes: Bound morphemes and free morphemes.

1.    Bound Morphemes

Segments that cannot stand alone and occurs with another segment are called Bound Morphemes. Bound morphemes are generally comprised of affixes: prefixes, suffixes and infixes. Some examples of bound morphemes are:

Walked: (Walk + ed) = root + suffix

Rewrite: (Re + write) = Prefix + root

Women: (Woman + plural) = root + infix (infix makes a change inside a stem/root word).

Bound morphemes can also be divided into two categories: inflectional morphemes and derivational morphemes

An inflectional morpheme is a suffix that is added to a word to assign a particular grammatical property to that word. For example, liste +ing = listening or boy+s = boys. They do not change the essential meaning or the grammatical category of a word..

Derivational morphemes change the grammatical categories of words e.g. the word ‘listener’ (noun) from ‘listen’ (verb).

2.    Free Morphemes

The morpheme that can stand alone as a single word is known as a free morpheme. The free morphemes are roots/stems that are identical to words. Examples of free morphemes are: Sun, hen, listen, and luck.

There are two sub-categories of free morphemes that are; functional morphemes and Lexical morphemes.

Functional Morphemes are set of functional words like conjunctions, prepositions, articles, pronouns, and auxiliary verbs and perform as a relationship between one lexical morpheme and another. Lexical morphemes are set of content words like nouns, verbs, adjectives, and adverbs.