This is a study of how the doctrine of impositio, the endowing of terms and propositions with a new signification, was treated in English obligationes texts from Walter Burley to the end of the fourteenth century. I show that in Burley and Ockham the rules for impositio were closely linked to the solution of insolubilia, but that this emphasis disappeared. I also show that Burley's doctrines were more honoured on the European continent than in England. I then examine the different doctrines of subsequent English logicians and how they were applied to selected sophismata. Here Roger Swyneshed and Richard Brinkley are particularly important, the first because of his nova responsio, and the second because of his doctrine that speakers can change imposition at will.