Verbal irony is a statement in which the meaning that a speaker employs 
is sharply different from the meaning that is ostensibly expressed. The 
ironic statement usually involves the explicit expression of one 
attitude or evaluation, but with indications in the overall 
speech-situation that the speaker intends a very different, and often 
opposite, attitude or evaluation
Dramatic Irony is the device of giving the spectator an item of 
information that at least one of the characters in the narrative is 
unaware of (at least consciously), thus placing the spectator a step 
ahead of at least one of the characters