The morphological structure of a word. Structural types of words. Derivational types of words. Derived words are composed of one root-morpheme and one or more derivational morphemes, e.g. But we cannot fail to perceive that root-words occupy a predominant place. Root- words also serve as parent forms for all types of derived and compound words. All the time the analysis is based on the patterns characteristic of the English vocabulary. Derivational types of word. The derivational structure of stems does not always coincide with the result of morphemic analysis. Derived words are those composed of one root- morpheme and one or more derivational morpheme.