1. A computer-implemented method comprising: providing a received input segment as a query to a search engine, the search engine searching an index of one or more collections of documents; receiving one or more candidate segments in response to the query; determining a similarity of each candidate segment to the received input segment; for one or more candidate segments having a determined similarity that exceeds a threshold similarity, providing a translated target segment corresponding to the respective candidate segment; and for a candidate segment having a determined similarity that does not exceed the threshold similarity: identifying one or more subsegments of the input segment, providing the one or more subsegments of the input segment to the search engine, and receiving one or more candidate subsegments corresponding to each of the one or more subsegments of the input segment.