Someone recently told me that, about 20 years ago, cars in Brunei started to install air-conditioners. And at the time it was a big deal to be able to afford a car with an air-conditioner. Then it became common for cars to have a sign on the back saying "No hand signals."
This sign is interesting because it has two very distinct meanings: at the basic level, it is (very helpfully) telling the driver behind you that, because your windows are closed, you are not able to use your hands to signal where you are going; but at a deeper level, it is saying "I am successful, because I can afford a car that has air-conditioning installed."
In reality, everything we say has a multiple range of meanings. Even if I just ask you a simple question like "How are you?", I am conveying a range of things: not only am I asking you how you are, but I am also telling you about my education (by the way I pronounce the words), how friendly I am (by the intonation I use), and a whole host of other things.
One of the basic lessons of pragmatics is that language is very rarely used just to convey simple factual information. It performs a wide range of other functions, and in many cases, these other functions are the real essence of the message.
