Learn how to say Concentrative correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word concentrate:
to come or cause to come to a single purpose or aim ⇒ to concentrate one’s hopes on winning
to make or become denser or purer by the removal of certain elements, esp the solvent of a solution
(transitive) to remove rock or sand from (an ore) to make it purer
(intransitive) often foll by on to bring one’s faculties to bear (on); think intensely (about)
a concentrated material or solution ⇒ tomato concentrate