According to McDonough (1986), the Natural Order Hypothesis is based on research findings (Dulay & Burt, 1974; Bailey, Madden, & Krashen, 1974), which suggested that the acquisition of grammatical rules follows a natural predictable order. This order is independent of the learner’s mother tongue, age, and setting. For example, in English language, the learner acquires the progressive –ing, plural –s, and active voice before he or she acquires third person –s, or passive voice. (Richards, J. Platt, & H. Platt, 1992).
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