In the state of the art society, it goes without saying that learning a language is important but learning a language without knowledge of cultural elements is sophisticated and usually results in ridiculous circumstances or even terrible, because of the inseparable relationship between culture and language. Additionally, in English as a Second Language (ESL) classroom, where students study to involve in the English native speaker culture, acquisition of cultural elements is probably essential. For the acquisition of culture in learning language, Brown (2000) illustrates that all of the culturally related aspects of language such as politeness, formality, metaphor, non-verbal communication are sociolinguistic competence. Therefore, the knowledge delivered in ESL classroom should also be included sociolinguistic competence. However, it is impractical to teach everything of sociolinguistic competence, unreasonable to expect learner can absorb them all and what to discipline should be based on learners’ need.In order to talk about the relationship between culture and language, it is believed that language is a part of culture according to many research like Brown (1994), Kramsch (1998), Everett (2012), etc. Brown (1994, 165) claims that language is a part of the culture and vice versa; it is impossible for a language learner to separate them but still maintain the important role of each other due to their complicated interlace. Hence, it is problematic for learners who can make a correct grammatical sentence but use it in an improper situation. However, language learners that lack knowledge about social rules of the intended listeners usually apply their own culture’s rules instead. For example, it seems unacceptable and impolite for a person comes from western culture to be asked about age, salary or marital status; but this problem can simply happen because these questions appear to be normal in some Asian-culture conversations. In order to avoid misunderstanding and impropriety in cross-cultural communication, a language learner not only learns grammar, vocabulary or pronunciation but also acquires cultural knowledge and manipulates it appropriately. Moreover, accomplishing both language and culture together can contribute to the advancement of acquisition of each other according to Brown (2007) because both language and culture carry the meaning of communication. While language contains meanings like syntax, semantics, and pragmatics (Brooks, 1997), culture consists of cultural meanings and context for language to be delivered and understood. It is also claimed by Tseng (2002, p.13) that language learners acknowledge of cultural background in pursuance of expression and raise their awareness in the target language. Therefore, gaining cultural proficiency and make use of it correctly is essential in the process of learning a language. Minze (1997, p. 8) states that albeit language learners manage to apply expressions into relevant circumstances, they have obtained sociolinguistic competence in that language. With the targeted learners of ESL classroom, the ones who will associate with the English native speaker culture, sociolinguistic competence is an essential part should be engaged in their curriculum.