Well, oftentimes, we just don’t know:
Our collective sense of irony, it seems, has never been in better health. We say, “How ironic!” as a politician’s hypocrisy is exposed; we laugh knowingly as Sacha Baron Cohen’s alter egos eviscerate their prey with perfect Socratic irony; we feel keenly the dramatic irony as Romeo takes his own life, thinking Juliet has killed herself. Irony, in all its forms, pervades our lives.
And yet, as soon as we move from being appreciative connoisseurs to active purveyors of irony, we run into difficulty. Verbal irony – the ostensibly simple act of stating something that is not meant – is a fragile thing, a contract between ironist and audience that is easily broken. Without mutual understanding, a theoretically ironic statement just does not work: a veiled compliment is mistaken for the insult behind which it is hidden, while an ironic expression of praise loses its critical sting. Sometimes, most simply, a meaningful statement becomes nonsensical.
Spoken irony, for the most part, avoids such pitfalls by virtue of tone of voice and the body language with which we accompany it. By cocking an eyebrow, by feigning enthusiasm or boredom, we give an attentive listener the clues they need to extract our true meaning. The problems most often arise not when we utter an ironic statement but when we try to write it down.
I don’t doubt that it is harder to convey irony via the written word than it is to convey spoken irony, but there are times when even efforts to convey irony through speaking get botched. One time, efforts to convey irony through singing famously collapsed–namely, because the singer in question (or the person who wrote her lyrics) had no conception whatsoever of what irony means.