1. A method, in a data processing system comprising a processor and a memory having instructions which, when executed by the processor, cause the processor to generate candidate answers to an explanatory question, the method comprising: responsive to identifying an input question as the explanatory question, decomposing, by the data processing system, the explanatory question into one or more explanatory queries; identifying, by the data processing system, one or more passages within a corpus of information that comprise an explanatory clause that provides an explanatory answer to the explanatory question based on pre-determined explanatory clause terms, wherein a passage within the one or more passages within the corpus of information that comprises the explanatory clause is identified by the method comprising: comparing, by the data processing system, each identified clause within a passage to a set of previously identified explanatory clauses; and responsive to the identified clause within a passage corresponding to one of the set of previously identified explanatory clauses, tagging, by the data processing system, the clause within the passage with an ‘EXPLANATORY’ tag; receiving, by the data processing system, hypothesis evidence with one or more passages comprising explanatory clauses from the corpus of information; generating, by the data processing system, one or more candidate explanatory answers based on hypothesis evidence; ranking and merging, by the data processing system, the one or more candidate explanatory answers; and outputting, by the data processing system, the one or more candidate explanatory answers.