In this talk we deal with logics with negation as the only connective. We study the relations between the main properties of pure negation and the various ways to define classical negation. We also study intuitionistic negation and minimal negation. We explain then how we can combine these different logics of negation with each other and with other pure logics: pure alethic modal logic, pure logics of conjunction, disjunction, implication. To develop this study we are using structural consequence operators, sequents systems and bivaluations.