Differences in the morphology of various languages are inevitably many and complex, and a detailed comparison of even two languages would require an extensive treatment. Nonetheless it is possible to characterize morphological patterns broadly in relation to complexity of word structure, richness of morphological devices, categories expressed morphologically and types of morphemes or of morpheme processes. In relation to word classes the discussion in this chapter will be restricted to major word classes – roughly those comparable to English nouns, verbs and adjectives – and more details will be given in the chapters on syntax.

Word structure

Although morphology is concerned with the structure and formation of words it will be convenient in some cases to take into account the forms called clitics. Clitics cannot occur flanked by pauses but show characteristics – that may vary from language to language – which set them aside from free forms (words) and bound forms (bound roots or stems, and affixes).

In some cases formulas of position classes of elements will be presented; in conjunction with information about the elements occurring in each position, these formulas give an approximate idea of a given system's potential for building words and of the complexity a word may have.