The class will discuss patterns found in Ossetic, Russian and Estonian. The empirical patterns will lead me to discuss issues related to Spec-formation, in particular when complex Specs close (I will suggest that they close as soon as possible), and how backtracking interacts with complex Specs. The tentative plan is to explore the option that backtracking to the Spec stage reopens the (previously closed) Spec for further merge F, allowing the Spec to grow despite the fact that Specs in general close as soon as possible. An even more tentative plan is to explore a system where if one backtracks into the Spec stage (because the spellout of a higher FP had failed), the feature F is merged both in the AUX workspace (making the Spec grow) and in the main workspace (making the main spine grow in parallel), leading to derivations closely resembling concord.