The present volume is a collection of papers selected from presentations given at two meetings of Generative Linguistics in Poland (GLiP) hosted by the University of Warsaw. GLiP is a series of conferences on various aspects of generative linguistics, with topics of the meetings alternating primarily between syntax, morphology and phonology. The present volume is an outcome of GLiP 3 and GLiP 4, devoted, to (morpho)phonology and (morpho)phonological acquisition. The common denominator of the papers included here is that all of them are set within constraint-based frameworks, mainly various versions of Optimality Theory, and apart from that, Government Phonology and Relational Network Theory. The languages under investigation include English, Greek, French, Polish, Russian, Ukrainian, viewed from the synchronic, diachronic and acquisitional perspectives.