Language is central to social interaction in every society, regardless of location and time period. Language and social interaction have a reciprocal relationship: language shapes social interactions and social interactions shape language. The basic premise of sociolinguistics is that language is variable and ever-changing. As a result, language is not uniform or constant. Rather, it is varied and inconsistent for both the individual user and within and among groups of speakers who use the same language. Sociolinguistics is the study of the connection between language and society and the way people use language in different social situations. It asks the question, “How does language affect the social nature of human beings, and how does social interaction shape language?” It ranges greatly in depth and detail, from the study of dialects across a given region to the analysis of the way men and women speak to each other in certain situations. One way that sociolinguists study language is through dated written records. They examine both hand-written and printed documents to identify how language and society have interacted in the past. This is often referred to as historical sociolinguistics: the study of the relationship between changes in society and changes in language over time. For example, historical sociolinguists have studied the use and frequency of the pronoun thou in dated documents and found that its replacement with the word you is correlated with changes in class structure in 16th and 17th century England. People adjust the way they talk to their social situation. An individual, for instance, will speak differently to a child than he or she will to their college professor. This socio-situational variation is sometimes called register and depends no only on the occasion and relationship between the participants, but also on the participants’ region, ethnicity, socioeconomic status, age, and gender. Researchers and scholars are currently using sociolinguistics to examine some interesting questions about language in the United States: There is vowel shift occurring in the North, in which pattered alterations to vowels is occurring in certain words. For example, many people in Buffalo, Cleveland, Detroit, and Chicago are now pronouncing bat like bet and bet like but. Who is changing the pronunciation of these vowels, why are they changing it, and why/how is it spreading? What parts of African American Vernacular English grammar are being used by white middle-class teenagers? For example, white adolescents might compliment a peer’s clothes by saying, “she money” or “he be jamming,” phrases that are associated with African Americans. What will be the impact on language in Louisiana due to the loss of monolingual French speakers in the Cajun region of Southern Louisiana? Will the French features of language be sustained even when these French speakers are gone? What slang terms do younger generations use to show their affiliation with certain subgroups and to distinguish themselves from their parents’ generation? For example, in the early 2000s, teenagers described things that they enjoyed as cool, money, tight, or sweet, but definitely not swell, which is what their parents would have said when they were teenagers. Sociolinguists also commonly study dialect, which is the regional, social, or ethnic variation of a language. For example, the primary language in the United States is English. People who live in the South, however, often vary in the way they speak and the words they use compared to people who live in the Northwest, even though it is all the same language. There are different dialects of English, depending on what region of the country you are in. Which words are pronounced differently according to age, gender, socioeconomic status, or race/ethnicity? For instance, African Americans often pronounce certain words differently than whites. Likewise, some words are pronounced differently depending on whether the person speaking was born after World War II or before. Which vocabulary words vary by region and time, and what are the different meanings associated with certain words? For example, in Southern Louisiana, a certain breakfast dish is often called lost bread while in other parts of the country, it is called French toast. Similarly, which words have changed over time? Frock, for instance, used to refer to a woman’s dress, while today frock is rarely used. Sociolinguists study many other issues as well. For instance, they often examine the values that hearers place on variations in language, the regulation of linguistic behavior, language standardization, and educational and governmental policies concerning language.