WordNet sense 1 (ready and willing to be taught):

docile

WordNet sense 2 (easily influenced):

malleable

WordNet sense 3 (easily managed (controlled or taught or molded)):

manipulable

WordNet sense 4 (readily reacting to suggestions and influences):

amenable, responsive

WordNet sense 5 ((often followed by `of' or `to') yielding readily to or capable of):

susceptible