Parts Of Speech

Read the following passage carefully and answer the questions that follow:
We know it well 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 uses 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 uses it as an instrument of thought. When the two women gossip over the fence or two men exchange greetings as they pass in the street, language is used to strengthen the bonds between the members of society. It seems that language is a multipurpose instrument. Language enables us to influence people's behaviour and help develop human co-operation. The human co-operation would be unthinkable without language as it makes human co-operation more thorough, more effective and more wide-ranging.
e.(iii) Write the adjective form of the word 'clarify'.