Pulverulent and liquid detergents contain (1) one or more anionic surfactants, one or more nonionic surfactants or mixtures thereof and (2) copolymers in amounts of from 0.1 to 15% by weight preparable by copolymerization of(a) from 10 to 55 mol % of a 1,2-di-C.sub.1 -C.sub.4 -alkoxyethylene,(b) from 10 to 60 mol % of a monoethylenically unsaturated dicarboxylic anhydride of from 4 to 8 carbon atoms,(c) from 0 to 60 mol % of a monoethylenically unsaturated C.sub.3 -C.sub.8 -monocarboxylic acid and(d) from 0 to 20 mol % of another monoethylenically unsaturated monomerand subsequent hydrolysis of the anhydride groups of the copolymerized monomer (b) or reaction of these groups with an alcohol or an amine.Preferred copolymers contain 1,2 dimethoxyethylene as the (a) monomer, maleic acid as the (b) monomer, and acrylic acid as the (c) monomer.