ABSTRACT
Only human beings make natural use of language. More than anything else, the ability to use language distinguishes human beings from other animals. There are many thousands of languages currently spoken and they differ radically from one another in many ways. The basic sound units of a language are known as phonemes and they differ from language to language. In all languages, this small stock of phonemes is used to build up many thousands of words. Words are constructed from smaller units known as morphemes; these are the smallest linguistic units that carry meaning. Different languages have very different sorts of syntax, just as they use different phonemes and have a different vocabulary Nevertheless, linguists believe that there are basic similarities underlying the syntax of all languages. In order to understand a language, listeners must be able to work out the phrase structure of the sentence; this is sometimes called the surface structure.
