Phrasal Substitution of Idiomatic Expressions

Idioms pose a great challenge to natural language understanding. A system that can automatically paraphrase idioms in context has applications in many NLP tasks. This paper proposes a phrasal substitution method to replace idioms with their figurative meanings in literal English. Our approach identifies relevant replacement phrases from an idiom’s dictionary definition and performs appropriate grammatical and referential transformations to ensure that the idiom substitution fits seamlessly into the original context. The proposed method has been evaluated both by automatic metrics and human judgments. Results suggest that high quality paraphrases of idiomatic expressions can be achieved.