If input plays a significant role in SLA, then the nextquestion is what kind of input is most helpful to the learner?Krashen (1982) defined that optimal input should (1) becomprehensible; (2) be interesting and/or relevant; (3) not begrammatically sequened; (4) be in sufficient quantity. Wemade some modifications to this list which may still not becomprehensive either. However, if the learner can be exposed toinput having these features, it is considered that acquisition ismore likely to occur. Such input should be comprehensible,authentic, attractive and interesting, interactive, up-to-date,culture-bearing, and in great quantity.