Morphology is the part of linguistics that deals with the study of words, their internal structure and partially their meanings. It is also interested in how the users of a given language understand complex words and invent new lexical items. As morphology is concerned with word forms it is akin to phonology (which describes how words are pronounced), it is also related to lexical studies as the patterns examined by morphology are used to create new words. Furthermore, it is also linked with semantics as it deals with the meanings of words.
Scholars differentiate between derivational morphology and inflectional morphology. The former is concerned with the relationships of different words, and with the ways in which vocabulary items can be built from some elements, as in un-speak-able; while the latter deals with the forms of one word that it takes up depending on its grammatical functions in a sentence. When it comes to English it appears that it rather takes advantage of derivational morphemes rather than inflectional ones.
Morphemes in morphology are the smallest units that carry meaning or fulfill some grammatical function. The word house itself consists of one morpheme, and because it can stand by itself it can be called a free morpheme. In the word houses there are two morphemes house, which is free, and s whish is a bound morpheme, because it cannot stand by itself as it would have no meaning. In the second example above the bound morpheme s was attached to house – a free morpheme, which in this case can be also called a stem. Stem is what a bound morpheme is attached to.
What is more, free morphemes can be subdivided into two categories: lexical morphemes and inflectional morphemes. Lexical morphemes are words that have some meaning – verbs, adjectives, nouns, like for example print, house, pretty, fire, go, girl. As there is no problem in adding new entities to this group of words they are treated as an open class of words. Functional morphemes, on the other hand, are a closed class of words, articles, prepositions, pronouns which do not carry any meaning on their own, but only fulfill a grammatical function.
Not only free morphemes are subdivided, there is a similar situation with bound morphemes which are subdivided into derivational and inflectional morphemes. Derivational morphemes are those morphemes which produce new words, or change the function of a word. It is achieved by means of prefixes or suffixes in case of English and infixes in other languages, like Arabic. Inflectional morphemes do not create new words, but only show grammatical functions of a word. A good example of an inflectional language could be Latin which has numerous case endings for nouns, as well as endings for verbs and adjectives.
Although this division seems to be quite clear cut there are come difficulties in analyzing certain words. Let’s take the word ‘reactor’ as an example. On the basis of the information above it could be stated that it consists of two morphemes: a stem actor and a derivational morpheme re-, which is obviously not the case. Moreover there are problems with the English plural, for instance it is easy to identify morphemes in the word houses (house – lexical free morpheme + s bound inflectional morpheme), but what about tooth and teeth? In order to solve such problems linguists introduced a term morphs which are the forms that represent morphemes. For instance in the word dogs, the morph s represents the morpheme ‘plural’ and in the word oxen the morph is en. There is a number of other peculiarities in a language like English, however morphology is still more highly developed for inflectional languages.