An introduction to study of the internal structure of words. The two main problems in morphology are (1) how to account for the surface variability of formatives (allomorphy) and (2) how to account for their combinatorial properties (morphosyntax). Beginning from the techniques and problems of structuralist morpheme analysis, two major approaches to allomorphy are introduced: the morpheme-based model and the word-based model. In morphosyntax, we concentrate on the question to what extent morphological combination is a matter of syntax vs. the lexicon. Emphasis is on constructing morphological hypotheses and linguistic argumentation. The assignments involve in-depth analyses of data from various languages.