Given any additive category C with split idempotents, pseudokernels and pseudocokernels, we show that a subcategory B is coreflective if, only it precovering, closed under direct summands each morphism in has pseudocokernel belongs to B. We apply this result its dual to, among others, preabelian pretriangulated categories. As consequence, of it, precovering taking cokernels. On the other hand, ...