what role did mr.keith play in the life of helen keller

Mr. Keith was one of the tutors who prepared Helen for college. He was from Cambridge. He taught Algebra, Geometry, Greek and Latin to Helen. He explained Helen what she did not understand, assigned work, corrected it and returned to Helen. His instructions were interpreted by Miss Sullivan. 
 

Apart from this, he even made mathematics quite interesting to Helen. He made Helen’s mind alert and eager. He trained her to reason clearly and to then seek conclusions calmly and logically.