It is a period of time(for the last month)not a definite time ,so present Perfect is perfect .
G gulesin Key Member Joined May 21, 2011 Member Type English Teacher Native Language Turkish Home Country Turkey Current Location Turkey May 29, 2011 #41 It is a period of time(for the last month)not a definite time ,so present Perfect is perfect .
N Nakuru Member Joined Jun 27, 2012 Member Type Student or Learner Native Language Spanish Home Country Spain Current Location Spain Jun 27, 2012 #42 It's present perfect because he still hasn't seen them.