When deciding on the best learners' dictionary for a specific user and a specific situation of usage one often has to make a choice between a monolingual and a bilingual learners' dictionary. This article discusses some aspects of the user-driven approach so prevalent in modernday lexicographic thought, focuses broadly on dictionary typology and takes a closer look at monolingual and bilingual learners' dictionaries. Some problems users experience when learning a new language, e.g. language distortion and problems related to the phenomenon of false friends, especially in closely related languages, are mentioned. It is indicated that a typological hybrid dictionary could assist certain users. The importance of an unambiguous identification of the relevant lexicographic functions is emphasised and the notions of function condensation and function merging are introduced. It is shown that the typological choice should be determined by a function-based approach to dictionary usage.