A method for controlling a system using natural language comprises a step of providing a plurality of string programme code components within the system. A string programme code component each comprises a definition string comprising an expression in natural language, and a programme code segment unambiguously assigned to the definition string which implements a functionality assigned to the expression in natural language. At least one of the string programme code components from the plurality of string programme code components further comprises a process for parameter input, wherein this string programme code component is configured to support a parameter input by means of which the functionality provided by the programme code segment of this string programme code component may be specified.