The University of Pennsylvania Working Papers in Linguistics (PWPL) is an occasional series published by the Penn Linguistics Club, the graduate student organization of the Linguistics Department of the University of Pennsylvania. The series has included volumes of previously unpublished work, or work in progress, by linguists with an ongoing affiliation with the Department, as well as volumes of papers from the NWAV conference and the Penn Linguistics Colloquium. We thank the Graduate Students Association Council of the University of Pennsylvania for financial support. This volume consists of selected papers presented at the 20th annual Penn Linguistics Colloquium and four papers written by linguists at the University of Pennsylvania.