Frontmatter -- Contents -- System and usage: (Never) mind the gap -- Part 1: System, usage, and variation -- Language variation and the autonomy of grammar -- The grammar of use and the use of grammar -- Looking for structure-dependence, category-sensitive processes, and long-distance dependencies in usage -- Variation in syntax: Two case studies on Brazilian Portuguese -- Part 2: Rare phenomena and variation -- Rare phenomena revealing basic syntactic mechanisms: The case of unexpected verb-object sequences in Mennonite Low German -- The no man's land between syntax and variationist sociolinguistics: The case of idiolectal variability -- What you like is not what you do: Acceptability and frequency in syntactic variation -- Part 3: Grammar, evolution, and diachrony -- "Intelligent design" of grammars - a result of cognitive evolution -- Syntactization, analogy and the distinction between proximate and evolutionary causations -- Gradual loss of analyzability: Diachronic priming effects -- How usage rescues the system: Persistence as conservation