Preposition placement, the competition between preposition stranding (What is he talking about?) and pied-piping (About what is he talking?), is one of the most interesting areas of syntactic variation in English. This is the first book to investigate preposition placement across all types of clauses that license it, such as questions, exclamations and wh-clauses, and those which exhibit categorical stranding, such as non-wh relative clauses, comparatives, and passives. Drawing on over 100 authentic examples from both first-language (English) and second-language (Kenyan) data, it combines experimental and corpus-based approaches to provide a full grammatical account of preposition placement in both varieties of English. Although written within the usage-based construction grammar framework, the results are presented in theory-neutral terminology, making them accessible to researchers from all syntactic schools. This pioneering volume will be of interest not only to syntacticians, but also second-language researchers and those working on variation in English.