Elliptic Constructions: Spotting Patterns in UD Treebanks

The goal of this paper is to survey annotation of ellipsis in Universal Dependencies (UD) 2.0 treebanks. In the long term, knowing the types and frequencies of elliptical constructions is important for parsing experiments focused on ellipsis, which was also our original motivation. However, the current state of annotation is still far from perfect, and thus the main outcome of the present study is a description of errors and inconsistencies; we hope that it will help improve the future releases.