title: Convert interrogative sentence to imperative sentence
body: <p>I'm trying to develop a Natural Language Interfaces to Database, and I'm just wondering if there is a library or an API (Java) that I can use to convert a question (interrogative sentence) to a command (imperative sentence).</p>
  
  <p>Ex : from "Which employees were born before 1970?" to "Get employees born before 1970."</p>