If a . system tries to transform an English question directly into the simplest possible formulation of the corresponding data base query, discrepancies between the English lexicon and the structure of the data base cannot be handled well. To be able to deal with such discrepancies in a systematic way, the PHLIQAI system distinguishes different levels of semantic representation; it contains modules which translate from one level to another, as well as a module which simplifies expressions within one level. The paper shows how this approach takes care of some phenomena which would be problematic in a more simple-minded.
