1. A method for aligning ambiguity in an input finite-state transducer (FST) having an input side, comprising the steps of: creating a left-deterministic input finite-state automaton (FSA) having a plurality of arcs by extracting the input side and determinizing the input side from left to right; and identifying each arc in the left-deterministic FSA, and for each such arc: identifying at least one corresponding sub-path in the input FST; and aligning the sub-path with at least one other corresponding sub-path by prepending arcs with symbols representative of an empty string.