Helpful
Part of speech: adjective
Definition: Furnishing help; giving aid; useful.
Example sentence: Therapists need to have a long experience in personal therapy to see what it's like to be on the other side of the couch and see what they find helpful or not helpful.
Cooperative
Part of speech: adjective
Definition: Ready to work with another person or in a team; ready to cooperate.
Part of speech: noun
Definition: A type of company that is owned partially or wholly by its employees, customers or tenants. Abbreviation: co-op.
Example sentence: As I've said, basketball has been, I think, a real cooperative venture. There have been a lot of people that have been involved in it: coaches, administrators - not recently - fans and nobody, nobody any more so than students over the years.