Word-formation is the brunch of lexicology which studies the derivative structure of existing words and the patterns on which a language builds new words.
Word-formation is the system of derivative types of words and the process of creating new words from the material available in the language after certain structural and semantic formulae and patterns. For instance the noun driver is formed after the pattern: v + suffix er.
The structural patterns with the semantic relations that they signal give rise to regular new creations of derivatives. e.g.: sleeper, giver, smiler. There are different classes according to different principles: morphological; syntactic; lexico-semantic.
There exist 4 main ways of word building in modern English: derivation affixation; composition; conversion; shortening abbreviation.
There are also secondary ways of word-building: sound interchange; stress interchange; sound imitation; blending; back formation; reduplication.
The conformity with structural types of words the following 2 types of word-formation distinguished: word-derivation; word-compounding.
Words created by word derivation have 1 derivational base and 1 derivational affixation. e.g.: overestimate.
Some derived words have no derivative affixes because derivation is achieved through conversion. e.g.: fall, n.; fall, v.
Word created by word composition have at least 2 bases. e.g.: ice-cold.
Word-formation may be studied from 2 angles: synchronically; diachronically.
Diachronically it is the chronological order of formation of 1 word from some other word that is relevant. Synchronically a derived word is regarded as having an even more complex structure that its correlated words regardless of the fact if it was derived from a synchro base or a more complex base.
Back-formation: e.g.: begger, n.-beg, v.
Sound and stress interchange may be regarded as ways of forming words only diachronically, because in middle English not a single word can be coined by changing the root vowel of q word or by shifting the place of the stress.
Sound and stress interchange in fact has turned into means distinguishing between words of different parts of speech. e.g.: sing, v.-song, n.
Sound interchange: vowel and consonant interchange. By means of vowel interchange we distinguish different parts of speech. e.g.: food, n.-to feed, v. In some cases vowel interchange is combined with affixation. e.g.: strong — strength; to sit — to set.
The type of consonant interchange typical of modern English is the interchange of a voiceless fricative consonant in a noun and the corresponding voice consonant in the verb. e.g.: use — to use.
There are some particular cases of consonants interchange. e.g.: speak — speech.
Consonant interchange may be combined with vowel interchange. e.g.: breath — to breathe.
Many English verbs of Latin French origin are distinguished from the correspondent noun by the position of stress. e.g.: export — to export. Some of the ways of forming words in present day English can be resorted to for the creation of new words whenever the occasion demands. These are called productive ways of forming words. Other ways cannot now produce new words and these are called non-productive. There are no absolutely productive means. Derivational patterns and affixes possess different degrees of productivity. All derivational patterns experience both structural and semantic constrains. The fewer are the constrains the higher the productivity is. The degrees of productivity: highly productive; semi-productive; non-productive.
