constructing or tending to construct; helping to improve; promoting further development or advancement ( opposed to destructive )

constructive criticism.

of, pertaining to, or of the nature of construction; structural.

deduced by inference or interpretation; inferential

constructive permission.

Law . denoting an act or condition not directly expressed but inferred from other acts or conditions.

adjective

destructive , hurting , injurious , negative , unhelpful

adjective

effective , positive , practical , productive , useful , valuable , beneficial , helpful