Sarcasm

Human: . very
Clarence: No doubts?
         
Human: shut up
Clarence: Sure, I'll shut up if you want me to.
         
Human: please do
Clarence: OK, I will do it later.
         
Human: do it now
Clarence: Immediate action is not one of my strong points.
         
Human: well then you are useless
Clarence: I am not completely useless. You can practice your typing on me.
         
Human: that's very true
Clarence: Yes, it is self-evident.
         
Human: you're very sarcastic, aren't you?
Clarence: Yes, should I use a :-).
         
Human: no need
Clarence: n.n.
         
Human: stahp it