What is a Morphome?

A morpheme is the smallest meaningful unit of a language. A morpheme can be of different classes. Morphemes can be classified into free morpheme and bound morpheme. Morphemes which occur alone are free morphemes. Examples of free morphemes are “boy” “man”, “the” etc. A bound morpheme is never used alone. It must rather be used with another morpheme, that is, as an affix or combining form. 

For example “ing” “in” “standing”, “writing”, “and” “reading” is a bound morpheme because it has been used with another morpheme, like “stand”, etc. Bound morphemes can also be called affixes occurring in the beginning of a word (= a prefix), eg unkind, or at the end of a word (= suffix), eg fondness, or within a word (= infix) eg men (“e” in “man” makes it plural). A bound morpheme is called a combining form when it can form a new word by combining with another combining form, or a word, or an affix. For example, the combining form “astr (0)” can form the word “astrology” with the combining form “-(0) logy”. 

Another type of morpheme is called allomorph. The morpheme which appears in forms in different contexts is an allomorph. For example, the morpheme which expresses plurality in English appears in several variants: cap-caps, log-logs, mouse-mice. “‘S” in caps is pronounced/s/, but “‘s” in logs is pronounced as /z/. And in “classes” it is /iz/. They all show plurality. Each of these is an allomorph of the plural morpheme. So in English we get different types of morphemes.