That's not a joke, really. OR That's not a joke really.
D derpington Member Joined Jan 5, 2013 Member Type Student or Learner Native Language British English Home Country UK Current Location UK Jan 5, 2013 #1 That's not a joke, really. OR That's not a joke really.
Barb_D Moderator Staff member Joined Mar 12, 2007 Member Type Other Native Language American English Home Country United States Current Location United States Jan 5, 2013 #2 Use the comma, or say "That's not really a joke."