The ingenious invention that enabled human beings to talk about everything
they can imagine, is syntax. Syntax is used to put together signs expressing relatively
simple meanings into sign combinations expressing more complex meanings. To express a meaning like ‘man killed lion’, we combine signs meaning ‘man’, ‘kill’, ‘past’, and ‘lion’, and we combine the same signs in a different way to express the meaning ‘lion killed man’. The English sign sequences man kill-ed lion and lion killed man are sentences, and the number of sentences in a language is infinite. Take any sentence in a language, and it is always possible to make it longer: man killed lion ⇒ the man killed the lion ⇒ the woman said that the man killed the lion ⇒ the old woman said that the young man killed the lion ⇒ the old woman said that the young man killed the lion that ate the antelope ⇒ the girl believed that the old woman said the young man killed the lion that ate the antelope – and so on infinitely.