THE INTERFERENCE MANIFESTATION THROUGH INTERLANGUAGE : A STUDY ON A MULTILINGUAL CHILD'S VERBAL PERFORMANCES· Heny HartonoZ and Tan Agung Baryono3 Abstract: Interference is often seen as an intrusion from the native language when a language learner is trying to perform the target language. In fact, it is more a part of the process of acquiring the target language which naturally happens before a language learner sucessfully achieves the target language proficiency. As a process rather than afinal product of learning language, it is hoped that it is not seen as a permanent incorrectness. The interference is manifested as an interlanguage. The interlanguage itself can be divided into 4 categories. namely overgeneralization, simplification, hypercorrection and avoidation. This research is trying to see the interference manisfestation of a multilingual child. Key words: interference, interlanguage. multilingual 1 This article is a development of a thesis. 2 Heny Hartono,S.S., M.Pd. +628122968851 is a lecturer at the Faculty of Letters, Soegijapranata Catholic University. She is a graduate from Gadjab Mada University and received her Master's degree in Education from Semarang State University. 3 Tan Agung Haryono is a graduate from the Faculty of Letters, Soegijapranata Catholic University. H. Hartono and T.A. Haryono, A Multilingual Child's Verbal Performances 87 REFERENCES Dulay, Heidi, Marina Burt, and Stephen Krashen. Language IWo. Oxford University Press: London, 1982. Ellis, Rod. Understanding Second Language Acquisition. Oxford: Oxford University Press, 1985. Grojean, F. "Bilingualism, Individual". In Journal on Concise Encyclopedia of Educational Linguistic. Edited by Bernard Spolsky. Oxford: Elsevier, 1999: 284-290.