Modal movement licensed by focus

This paper investigates the high position of root modals (such as keyi ‘may’) in Chinese, and its interaction with focus interpretations. We address a long-standing puzzle concerning their position: A-not-A questions appear to exceptionally license an otherwise unavailable high position of root modals preceding subjects and/or topics. Upon closer examination, we observe that (i) A-not-A questions do not always license the high position of root modals and that (ii) the position of focus plays a crucial role in licensing high modals. We propose that root modals undergo head movement across a focused element to the high position, and this movement is constrained by a focus version of output economy.