These papers, dedicated to Osvaldo Jaeggli by some of his friends and colleagues, canvas a variety of topics central to the current development of syntactic theory. Anne Rochette and Mario Montalbetti tackle subjects concerning the relationship between argument structure and grammatical functions. Dominique Sportiche and Joseph Aoun take up two particularly puzzling aspects of the syntax of clitics; Sportiche provides a new analysis of critic inversion constructions in French, and Aoun offers a novel theory of critic doubling constructions, drawing on Arabic data. Maria Luisa Zubizarreta argues that inverted subjects in Spanish occupy a different structural position than the parallel inverted subjects of French or Italian, and relates this to other differences in the principles of word order these languages obey. Finally, the articles by Mamoru Saito and Keiko Murasugi, Hagit Borer and Hilda Koopman all touch on the rapidly developing syntax of Determiner Phrases. Together these articles represent the ongoing transition from models of syntactic variation that employ static sets of principles with open parameters in them.