This paper examines cyclical changes in comparative subclauses, showing how operators are reanalysed as complementisers via the general mechanism of the relative cycle, and how this is related to whether certain lexical elements have to be deleted at the left periphery. I also show that only operators appearing without a lexical XP can be grammaticalised, which follows from the nature of the formal features associated with the various operator elements. Though the main focus is on Hungarian historical data, the framework can be applied to other languages too, such as German and Italian, since the changes stem from general principles of economy.
