Use of copolymers containing sulfonic acid groups which comprise (a) 30 to 95 mol % of at least one monoethylenically unsaturated carboxylic acid, one monoethylenically unsaturated carboxylic ester or one water-soluble salt of a monoethylenically unsaturated carboxylic acid, (b) 3 to 35 mol % of at least one monomer containing sulfonic acid groups of the formula I ##STR00001## in which the variables have the following meanings: R is hydrogen or methyl; X is a chemical bond or --COO--R.sup.1--; R.sup.1 is unbranched or branched C.sub.1-C.sub.4-alkylene; M is hydrogen, alkali metal or ammonium, and (c) 2 to 35 mol % of at least one nonionic monomer of the formula II ##STR00002## in which the variables have the following meanings: R.sup.2 is hydrogen or methyl; R.sup.3 is a chemical bond or unbranched or branched C.sub.1-C.sub.6-alkylene; R.sup.4 are identical or different unbranched or branched C.sub.2-C.sub.4-alkylene radicals; R.sup.5 is unbranched or branched C.sub.1-C.sub.6-alkyl, C.sub.5-C.sub.8-cycloalkyl or aryl; n is 3 to 50, in random or block copolymerized form, as additive for detergents and cleaners.