Keywords: five functions of vocabulary, geoffrey leech Language plays an essential role in human being lives. It really is a social sensation. One of the key goals of language is to communicate with people and understand them. When someone talks, he intends a particular purpose. He would like to convey some text through that dialect. A person uses his words to numerous different purposes for example, to express his thoughts, to require help and to apologize. In truth, we use terminology in many various ways, many of these are, the informational, the expressive, the directive, the phatic, the cosmetic. We use language and that vocabulary is a part of society. Actually, any vocabulary varies regarding to, the nature of the population, what kind of individuals, and their behaviour. People use terminology according to their situation.