Linguistic morphology

Linguistic morphology studies how words are structured from morphemes and how their forms relate to grammatical functions and meaning. It distinguishes reusable patterns from merely splitting a spelling into arbitrary pieces. Spoken and signed languages can both have morphological structure.^[ref]

For example, replayed can be analyzed as re- plus play plus -ed: repetition and past marking combine with a lexical base. The segmentation predicts relationships with play, replay and played, rather than only describing one isolated word. Inflection marks grammatical alternatives, while derivational morphology can form new lexical items. A computational analyzer can represent permitted combinations with a finite-state machine; an analysis is useful when it generalizes to new forms while rejecting combinations outside the specified grammar.