The Oxford English Dictionary defines Sarcasm as being ‘The use of irony to mock or convey contempt’. Sarcasm is often something that is said ironically. Basically, someone is saying the opposite of what they actually mean.
Say you have met up with your friend for a coffee on a cold and wet day. They say to you ‘Lovely weather we’re having’. Obviously, they are being sarcastic, because the weather is not lovely. In this case, sarcasm is used as a light-hearted way of making light of the terrible weather.
Most people who understand sarcasm would find this funny as they are in on the joke. The can see the irony in this statement.
The tone of voice used is also important. If it was a sunny day, and someone said: ‘Lovely weather we’re having!’, they would probably say it in a high-pitched or excitable sounding way. If they said it on the wet and cold day, they could probably say it in a lower sounding pitch to convey their contempt and sarcasm.
In both cases, inflection is being used. The inflection goes up (into a higher pitch) if they are being genuine and goes down (into a lower pitch) if they are being sarcastic.
Sarcasm may also be denoted in written pieces of work and books as a sentence that has an exclamation mark in brackets at the end. For example, ‘Well, what a surprise (!)’ Here, the exclamation mark is used to show contempt and to mock someone or something.
Many other languages use inflections, but not always to denote whether or not someone is being sarcastic or genuine. It can be confusing if you do not speak English as a first language.
A good way to try and learn how sarcasm is used is by watching British comedy shows. These could be things like sitcoms, panel shows and comedy films.
That way, you’ll be able to pick up and recognise when sarcasm is used for exaggerated effect. You’ll hopefully be able to better understand when and how it is used in everyday conversations in the UK.
You could even try being sarcastic yourself! I would probably advise you to practise with friends though, you don’t want to be accidentally offending your lecturer or someone in a shop!