Read the following passage carefully and answer the questions that follow:
It is clear that language is used for more than one purpose. The man who hits his thumb nails with a hammer and utters a string of curses is using language to relieve his feeling and needs no audience but himself. But when a philosopher uses language to clarify his ideas on a subject, he is using it as an instrument of thought. When two women gossip over the fence or two men exchange greetings as they pass in the street, language is being used to strengthen the bonds between the members of society. Language, it seems, is a multipurpose instrument. One function, however, seems to be basic — language enables us to influence people's behaviour and thereby makes human co-operation possible. Some animals co-operate especially the social animals like bees and ants, but human co-operation is more thorough, more detailed, more effective than that found anywhere in the animal kingdom. The human co-operation would be unthinkable without language.
(c) For what purpose do the two women and two men use language?