[ubuntu] sudo pm-hibernate doesn't work, nothing happens

Hi, everyone! I am trying to get my newly switched to Ubuntu 16.04 LTS, installed on a HP 15-f039wm to hibeate but I have not had success. I have a 500GB HDD and 8GB RAM. I tried creating a swap file which I think is enabled, but still when I type "sudo pm-hibeate" nothing happens, I had even tried command lines from similar threads, still nothing. I just switched from Windows, I feel awkward but intrigued at the same time, I have seen pretty Linux savvy people in this forum, please help. Thank you.