This study investigates the effects of classroom interactions between a) students and students and b) students and teachers on the learning of English passivization by L1 Chinese adult learners of English as a foreign language during the language input and output treatments. In phase 1, both groups were asked to read and underline the input material. After the materials were collected, the participants were required to produce the first reconstruction. After having been exposed to the same input material again, the participants produced the reconstruction the second time. In phase 2, participants wrote a short passage on a given topic and were presented a sample of the writing provided by the participating teacher. The results of this study suggest that classroom interaction and the language output may trigger learners to notice the target form and have a positive effect on improving the learning of a foreign language.