Do we need to care about grammar, even if ungrammatical utterances can be understandable? Grammar is a set of rules of how a phrase or clause should be organized in both speaking and writing. Each language has its own format. Studies of finding the so-called “linguistic universals” have given rise to two principles, “prescriptivism” and “descriptivism.” From former’s view, such rules should be observed while from the latter’s, any changes in language should be considered as natural occurrences and an essential nature of language. Standardized written forms have been established due to the necessity of communication among the wider range of people. Such forms have been pervaded by “language purists,” and then those forms have been applied to spoken language as well. The usage strayed from those forms has been judged as degeneracy and lower rank people’s tongue. Lately, however, dissimilarity between spoken and written language has been recognized. “Prescriptivism” and “descriptivism” aren’t necessarily seen as dichotomy between the two. “Prescriptivism” gives us a standardized set of patterns at certain times, which plays a major role in black-tie occasions. It also makes it less difficult for non-native speakers to communicate with each other. “Descriptivism” is helpful to understand the mechanism of our mind and our gut feelings’ influence on our perception of this world. Grammar is an ideal tool as it reflects how we use language regularly. Therefore, we, language users, are the ones who ceaselessly alter grammar. As language and grammar are alike, each of us plays part in knitting this marvelous and intricate tapestry: grammar.