Linguists study the underlying principles of human languages. They are interested in understanding how children learn their native language without much instruction before they enter school and how people speak and understand sentences they have never heard before. Linguists also study language change through time. Some linguists study how damage at different locations in the brain causes different types of linguistic problems.<br><br>Rather than attempting to learn many languages, linguists search for the organizational principles of the world's languages.<br><br>The description of formal patterns of human language has a number of applications. Linguistics is linked with anthropology and other social sciences in studying how language use relates to culture, region, class, and gender. It is connected to psychology, speech, and hearing in studying how children learn language, how speakers process and interpret language, and how injuries and disorders affect both production and perception of speech.