This paper studied the characteristics of "foreigner talk" and "teacher talk" in adult Chinese acquisition. Based on the vivid examples, the study showed that in order to communicate withthe non-native speakers, Chinese native speakers (including the language teachers) made some adjustments in their speech. The adjustments included input adjustments and interactional adjustments. From the analysis of the "foreigner talk" and "teacher talk", we could find out the learning process of the second language learner. Meanwhile, the study also inspired the Chinese language teaching.