Sheffield submissions for the WMT18 quality estimation shared task

�� 2018 The Authors. Published by Association for Computational Linguistics. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher���s website: http://dx.doi.org/10.18653/v1/W18-6463In this paper we present the University of Sheffield submissions for the WMT18 Quality Estimation shared task. We discuss our submissions to all four sub-tasks, where ours is the only team to participate in all language pairs and variations (37 combinations). Our systems show competitive results and outperform the baseline in nearly all cases.Carolina Scarton is supported by the EC project SIMPATICO (H2020-EURO-6-2015, grant number 692819). Frederic Blain is supported by the Amazon Academic Research Awards program