A computer implemented system creates natural language paraphrases of information contained in a logical form, where the logical form may be a representation of a natural language expression. (Logical forms are widely used by database query systems and machine translation systems and are typically forms of first-order logic, with the possible addition of higher-order operators.) The paraphraser is implicitly defined via the BNF description of CLF (Baclis-Naur Forms) of Initial Trees and of the paraphrase rules. The paraphraser uses a technique for mapping logical forms to natural language. The natural language paraphrases which are created could be used either as input to a query system, as part of a machine translation system, or to generate natural language corresponding to an interpretation created by a natural language database query system of a user's query for the purpose of verification of the paraphrase by the user.