1. Toward an integrated approach to syntactic variation: A retrospective and prospective synopsis (by Cornips, Leonie); 2. Part 1: Aspects of modularity; 3. A modular approach to sociolinguistic variation in syntax: The gerund in Ecuadorian Spanish (by Muysken, Pieter); 4. Selective optionality in language development (by Sorace, Antonella); 5. Syntactic variation and spoken language (by Cheshire, Jenny); 6. Part 2: Individual speaker variability and methodological innovation; 7. Idiolectal variation and syntactic theory (by Henry, Alison); 8. Focus raising: A paradigmatic example of the treatment of syntactic variation (by Gervain, Judit); 9. Part 3: Syntactic variability, social stratification and real/apparent time; 10. Variation and the minimalist program (by Adger, David); 11. Principles and parameters in change (by Gelderen, Elly van); 12. Morphosyntactic variation and theory: Subject-verb agreement in Acadian French (by King, Ruth); 13. Part 4: Syntactic variability across geographical space; 14. Word order variation in three-verb clusters and the division of labour between generative linguistics and sociolinguistics (by Barbiers, Sjef); 15. The third dimension of person features (by Beninca, Paola); 16. Index