Which of the speakers words provide clues to the tone ?

Irony can be tough to write because first you have to notice something ironic to write about a situation, which is a kind of insight. That’s also why it’s a fairly impressive writing technique. So the trick is not to practice writing irony but to practice noticing it. Look around you every day, and you will see plenty of ways in which ordinary expectations are contradicted by what happens in the real, unpredictable world.As you look around for irony, take care to avoid the pitfall of confusing irony with coincidence. Often coincidences are ironic, and often they are not. Think of it this way: a coincidence would be if firemen, on the way home from putting out a fire, suddenly got called back out to fight another one. Irony would be if their fire truck caught on fire. The latter violates our expectations about fire trucks, whereas the former is just an unfortunate (but not necessarily unexpected) turn of events.

Another way of putting it is this: coincidence is a relationship between  facts (e.g. Fire 1 and Fire 2), whereas irony is a relationship between a fact and an expectation and how they contradict each other.

When to use irony

Irony belongs more in creative writing than in formal essays. It’s a great way of getting a reader engaged in a story, since it sets up expectations and then provokes an emotional response. It also makes a story feel more lifelike, since having our expectations violated is a universal experience. And, of course, humor is always valuable in creative writing.

Verbal irony is also useful in creative writing,