Knowledge Base Population (KBP, e.g.: Riedel et al., 2013; Sterckx et al., 2016) attempts to identify facts within raw text and convert them into triples consisting of a subject, object and the relation between them. One common form of this task is slot filling (Surdeanu and Heng, 2014) , in which a knowledge base (KB) query, such as place of birth(Obama, ?) is applied to a set of documents and a set of slot fillers is returned. By converting such KB queries to natural language questions, <cite>Levy et al. (2017)</cite> showed that a question answering (QA) system could be effectively applied to this task.