This volume presents the intermediate results of the international "Crosslinguistic Project on Pre- and Protomorphology in Language Acquisition" co-ordinated by Wolfgang U. Dressler in behalf of the Austrian Academy of Sciences. It continues the series of publications started with Dressler & Karpf 1995, Dressler 1997, Dziubalska-Kolaczyk 1997, Gillis 1998, Bittner, Dressler and Kilani-Schoch 2000 as well as individual publications of the project participants. About the project - take the introduction from Dressler (manuscript for San Sebastian). The book includes several introductory chapters (Dressler & Kilani-Schoch, Stephany, Voeikova) written by the project co-ordinators on the base of the written reports of participants and several studies on the acquisition of noun and verb morphology in the transitory phase from pre- to protomorphology (for definitions see Bittner, Dressler and Kilani-Schoch 2000: 3 ff.) and in the protomorphological phase in eight languages (German, Finnish, French, Yucatec Maya, Italian, Lithuanian, Russian and Spanish). Both inflectional and derivational morphology is observed in nouns, including such topics as compounding, diminutive formation, case and number distinctions. Verbs are described from the point of view of inflectional morphology and agreement. Case vs. number and person - heterogeneous. Number and person - crosslinguistically - the difference is in the type of marking and shape (more patterns, inflectional classes etc. vs. phonological harmony). The set of forms is comparable. Case - the set of forms is hardly comparable without grouping. Big number of forms in the paradigm does not aggravate their acquisition if there are no inflectional classes. On the other hand, small number of distinct inflectional forms, analytical marking, other means to express case distinctions may slow the process.