If we describe a w o r d as an autonomous unit of language in which a particular meaning is associated with a particular sound complex and which is capable of a particular grammatical employment and able to form a sentence by itself , we have the possibility to distinguish it from the other fundamental language unit, namely, the morpheme.
A morpheme is also an association of a given meaning with a given sound pattern. But unlike a word it is not autonomous. Morphemes occur in speech only as constituent parts of words, not independently, although a word may consist of a single morpheme. Nor are they divisible into smaller meaningful units. That is why the morpheme may be defined as the minimum meaningful language unit.
According to the role they play in constructing words, morphemes are subdivided into roots and affixes. The latter are further subdivided, according to their position, into prefixes, suffixes and infixes, and according to their function and meaning, into derivational and functional affixes, the latter also called endings or outer formative s.
When a derivational or functional affix is stripped from the word, what remains is a stem (or astern base). The stem expresses the lexical and the part of speech meaning. For the word hearty and for the paradigm heart (sing.) — hearts (pi.)1 the stem may be represented as heart-. This stem is a single morpheme, it contains nothing but the root, so it is a simple stem. It is also a free stem because it is homonymous to the word heart.
A stem may also be defined as the part of the word that remains unchanged throughout its paradigm. The stem of the paradigm hearty — heartier — (the) heartiest is hearty-. It is a free stem, but as it consists of a root morpheme and an affix, it is not simple but derived. Thus, a stem containing one or more affixes is a derived stem. If after deducing the affix the remaining stem is not homonymous to a separate word of the same root, we call it abound stem. Thus, in the word cordial ‘proceeding as if from the heart’, the adjective-forming suffix can be separated on the analogy with such words as bronchial, radial, social. The remaining stem, however, cannot form a separate word by itself, it is bound. In cordially and cordiality, on the other hand, the derived stems are free.
Bound stems are especially characteristic of loan words. The point may be illustrated by the following French borrowings: arrogance, charity, courage, coward, distort, involve, notion, legible and tolerable, to give but a few.2 After the affixes of these words are taken away the remaining elements are: arrog-, char-, com-, cow-, -tort, -volve, not-, leg-, toler-, which do not coincide with any semantically related independent
Roots are main morphemic vehicles of a given idea in a given language at a given stage of its development. A root may be also regarded as the ultimate constituent element which remains after the removal of all functional and derivational affixes and does not admit any further analysis. It is the common element of words within a w o r d-f a m i 1 y. Thus, -heart- is the common root of the following series of words: heart, hearten, dishearten, heartily, heartless, hearty, heartiness, sweetheart, heart-broken, kind-hearted, whole-heartedly, etc. In some of these, as, for example, in hearten, there is only one root; in others the root -heart is combined with some other root, thus forming a compound like sweetheart.
We shall now present the different types of morphemes starting with the root. It will at once be noticed that the root in English is very often homonymous with the word.
A suffix is a derivational morpheme following the stem and forming a new derivative in a different part of speech or a different word class, c f. -en, -y, -less in hearten, hearty, heartless. When both the underlying and the resultant forms belong to the same part of speech, the suffix serves to differentiate between lexico-grammatical classes by rendering some very general lexico-grammatical meaning. For instance, both -ify and -er are verb suffixes, but the first characterizes causative verbs, such as horrify, purify, rarefy, simplify, whereas the second is mostly typical of frequentative verbs: flicker, shimmer, .twitter and the like.
A prefix is a derivational morpheme standing before the root and modifying meaning, c f. hearten — dishearten. It is only with verbs and statives that a prefix may serve to distinguish one part of speech from another, like in earth n -unearth v, sleep n — asleep (stative). It is interesting that as a prefix en- may carry the same meaning of being or bringing into a certain state as the suffix -en, c f. enable, encamp, endanger, endear, enslave and fasten, darken, deepen, lengthen, strengthen.