Swain (1985) pointed out the need for increased modified output in the classroom in order to encourage learners to engage in more syntactic processing and, thus, make more form-meaning connections. Research in content-based instruction (CBI) ( Musumeci, 1996; Pica, 2002) has revealed few occasions of pushed modified output from learners. Therefore, one questions whether CBI classes are effective in promoting and developing not only content knowledge, but also form-function abilities, specifically in the expressive skills. Second language (L2) learners from a 3rd semester university-level content-based geography course (N = 43) completed 2 (or 3) production tasks at the beginning and end of the regular semester. The findings revealed that learners made significant improvements in both content knowledge and functional linguistic abilities. However, it is possible that that latter still has room for improvement.