¬¬THE NEGATIVE IMPACT OF NIAS LANGUAGE INTERFERENCE IN LEARNING INDONESIAN LANGUAGE

Most of people in the world and also Indonesian speakers are bilingualism, who use two languages; Indonesian and mother tongue. Commonly, both languages influence one another, which finally create a new phenomenon of language called interference of language. Interference of language is a form of an impact of mother tongue towards second language, which creates an error in the second language. The error occurs because the mother tongue language and the second language have different structure and different way in using the language. In this research, the writer finds out that the ability of someone in mastering the second language will always be influenced by the mother tongue. As a real case for Nias speakers, they make mistakes and errors when they speak in Indonesian, especially in phonological and grammatical structure. The mistake occurs because phonological and grammatical in their mother tongue are still used in second language, thus it makes the second language invalid in the way of norm and rule.  From the result of the research, it can be concluded that Nias speakers interfere Indonesian in their daily conversation. The interference can be existed as a form of the impact of mother tongue to second language. In this research, there are three interferences of Nias speakers that have been found by the writer. First, Nias speakers omit the final consonant of words when speaking in Indonesian, it is because in Li Niha there is no final consonant of words but only final vowel. Second, Nias speakers also create a redundancy when they are speaking Indonesian, it is because they are usually add some words in their speech in order to emphasize their statement. Third, Nias language and Indonesian language have different structure in arranging sentences. Based on that difference, Nias speakers oftentimes invert the words in sentences. So, the writer concluded that all of these aspects are the aspect which influences Nias speakers to interfere the second language.   Keywords: Sociolinguistics, Interference, Mother tongue, Bilingualism, Phonological, Grammatical structure..