This book aims to provide a considerably detailed, integrated and methodologically grounded study of at within the cognitive framework. Assuming the non-arbitrary quality of the mental lexicon and highly creative nature of the human conceptual system, it is posited that each preposition has a primary sense which interacts with a highly constrained set of cognitive principles to derive a set of additional distinct senses, forming a motivated semantic network. The present analysis also reveals that at is remarkably coherent in its metaphoric and metonymic manifestations in that there exists a high degree of family resemblances between all the uses discussed in this study. Theoretical investigation is set against empirical data to offer support for the claim that both native and advanced foreign language speakers appear to possess a high awareness and intuition about the proper conceptualization of individual at-senses.