Word-building is one of the main ways of enriching vocabulary. There are four main ways of word-building in modern English: affixation, composition, conversion, abbreviation. There are also secondary ways of word-building: sound interchange, stress interchange, sound imitation, blends, back formation.
AFFIXATION
Affixation is one of the most productive ways of word-building throughout the history of English. It consists in adding an affix to the stem of a definite part of speech. Affixation is divided into suffixation and prefixation.