1. A communication supporting apparatus, comprising: a supplemental example storing unit that stores a source language interpretation which is an interpretation of a semantic content of a source language sentence to be translated, and a supplemental example sentence which is an example of a sentence for supporting the semantic content, in association with each other; an input accepting unit that accepts the source language sentence input by a user; an analyzing unit that analyzes the semantic content of the source language sentence and outputs the source language interpretation; a search unit that searches for the supplemental example sentence associated with the source language interpretation from the supplemental example storing unit; and a translation unit that translates the source language sentence and the supplemental example sentence into a target language.