Many animal and even plant species communicate with eachother. Humans are not unique in this capability. Therefore, human 1language is unique in being a symbol communication system that is 2learned instead of biologically inherited. A word is one and more sounds that in combination with aspecial meaning assigned by a language. The symbolic meaning of 3words can be so powerful that people are willing to risk their lives for them or take the lives of others. A major advantage of human language is being a learned 4symbolic communication system is that it is infinitely flexible.Meanings can be changed and new symbols create. This is 5evidenced by the fact which new words are invented daily and the 6meaning of old ones changes. Languages evolve in response tochange historical and social conditions. Some language 7transformations typically occur in a generation or more. For instance, the slang words used by your parents were very differentfrom it that you use today. You also probably are familiar with many 8technical terms, such as " text messaging" and " high definition TV" , which were not in general use even a decade ago. Language and speech are not the same thing. Speech is abroad term simply referred to patterned verbal behavior. In contrast, 9a language is a set of rules for generating speech. A dialect is a variant of a language. If associated with a geographically isolatedspeech community, it is referred to a regional dialect. However, if 10it is spoken by a speech community that is merely socially isolated, it is called a social dialect which is mostly based on class, gender, age, and particular social situations.