This study investigates the effects of the flipped classroom approach on five aspects of written communicative competence of learners of English as a foreign language (EFL): lexis, syntax, cohesion, pragmatics, and discourse. It experimented on two groups of Chinese undergraduates in a regular college English course, using a flipped learning approach on one group and a traditional lecture approach on the other. The results from a pre-test and post-test revealed that the flipped approach had differential effects on the aforementioned five sub-competencies. More specifically, the flipped group's overall performance was better than the control group in the post-test, indicating an overall positive role of the flipped approach on EFL learners' development of communicative competence. However, significant group differences were found only on the learners' lexical, cohesive, and pragmatic competencies, and not on their syntactical or discourse competencies. These findings thus provide further insights on how the flipped method might be strategically used to facilitate the learners' language development.