This study addresses EFL task motivation in the process-oriented framework. There has been little research of the developmental process of L2 motivations in the formal classroom contexts, even though a substantial body of research has investigated L2 motivations cross-sectionally. As a follow-up application of Kang (2013), this study investigates the relationships between EFL college students`` task performances and motivations in the three phases of formal classrooms using questionnaires: pre-actional, actional, and post-actional. The findings showed that motivations were not influential on task performances during the pre-actional phase, but motivational intensity and WTC (Willingness To Communicate) were significantly correlated with task performances such as noticing and successful uptake during the actional phase. The task performances positively influenced L2 achievement at the end of the grammar instructions through mediating L2 motivations during the actional phase. The findings suggest that we need more research in the areas of the task types and motivational factors in the formal lassroom contexts in the future.