Morpholexical rules in Polish The aim of the paper is to suggest a unified account of all passive and passive-like constructions in Polish which have traditionally been described as passive, mediopassive, or impersonal passive, and which have presented problems of analysis. I would like to propose a tripartite classification of all the relevant constructions into passive, impersonal, and reflexive (the last category including the traditional 'mediopassive/impersonal reflexive'), to show that each category involves a different operation and to demonstrate how the type of the operation accounts for the distinctive properties of the construction. The analysis assumes a single derivational level of representation for a predicate which (a) states its subcategorization requirements, (b) singles out the ('deep', or 'logical') subject argument (if there is any), and (c) is associated with, though not dependent on, a semantic level from which thematic roles are projected onto the argument structure. I would like to propose that both passivization and impersonalization are subject-sensitive. Passivization, which delinks the highest argument from its pre-assigned subject function, is subject-sensitive on its input (therefore it does not apply to unaccusatives). It results in a passive participle stem and feeds adjectival formation. Impersonalization, which is a dedicated subjectless construction, is subject-sensitive on its output (therefore it can apply to unaccusatives), and results in a non-adjectival form. Reflexivization is an operation which reflects dissociations between the argument structure and the thematic structure of the predicate. It is passive only when passivization occurs independently, and impersonal only when impersonalization occurs independently, i.e. it overlaps with, but is distinct from both passivization and impersonalization. When arguments become dissociated from their thematic roles, they are filled by 'dummies' - reflexive particles of three different types, depending on the nature of the dissociation. In the light of this analysis, constructions which have traditionally been called 'mediopassive' result from the dissociation of the highest argument from its thematic role of Agent, without the delinking of the subject function (i.e. without passivization). In contrast to passivization and impersonalization, reflexivization can be object-oriented, and the analysis provides a systematic account of all possible reflexive constructions in Polish which involve a valency alternation. The analysis assumes the notion of lexical mapping that has been prominent in LFG, but it makes use of the insights of various accounts: the typological accounts based on traditional views (such as Siewierska 1988), as well as the various generative approaches, including the insights expressed in the framework of Relational Grammar (such as Perlmutter 1978; and Rosen 1984), LFG (Bresnan & Kanerva 1992; Bresnan & Zaenen 1990), HPSG (Manning & Sag 1999; Avgustinova, Skut & Uszkoreit 1999), and in the P&P literature (Babby 1989; Rivero 1999). REFERENCES Avgustinova, T., W. Skut & H. Uszkoreit (1999) 'Typological similarities in HPSG: A case study on Slavic verb diathesis', to appear in: Borsley, R.D. & A. Przepiorkowski (eds) Slavic in HPSG. CSLI Babby, L.H. (1989) 'Subjectlessness, external subcategorization, and the Projection Principle', ZMSFL 32(2): 7-40 Bresnan, J. & J.M. Kanerva (1992) 'Locative inversion in Chichewa: A case study of factorization in grammar', in: Stowell, T. & E. Wehrli (eds) Syntax and Semantics 26: Syntax and the Lexicon. Academic Press Bresnan, J. & A. Zaenen (1990) 'Deep unaccusativity in LFG', in: Dziwirek, K., P. Farrell & E. Mejias-Bikandi (eds) Grammatical Relations. A Cross-Theoretical Perspective. CSLI Manning, C.D. & I.A. Sag (1999) 'Dissociations between argument structure and grammatical relations', in: Webelhuth, G., J.-P. Koenig & A. Kathol (eds) Lexical and Constructional Aspects of Linguistic Explanation. CSLI Perlmutter, D.M. (1978) 'Impersonal passives and the unaccusative hypothesis', BLS 4: 157-189 Rivero, M.-L. (1999) 'Impersonal "sie" in Polish: a pronominal anaphor' (ms) Rosen, C.G. (1984) 'The interface between semantic roles and initial grammatical relations', in: Perlmutter, D.M. & C.G. Rosen (eds) Studies in Relational Grammar 2. University of Chicago Press Siewierska, A. (1988) 'The passive in Slavic', in: Shibatani, M. (ed.) Passive and Voice. John Benjamins.