한국 친구와 자주 만나서 이야기하다 보면 잘하게 될 거야.
If you and your Korean friends frequently meet and talk, you will get good (at Korean).
만나다 (to meet) can be used as a transitive verb and as an intransitive verb. If we say 친구를 만난다 (I meet my friend), we are using "meet" as a transitive verb. If we say 친구와 만난다 (My friend and I meet), we are using "meet" as an intransitive verb.
I think there are probably good reasons for distinguishing between the transitive "meet" and the intransitive "meet," but I am not sure what they are, and I am not in a very contemplative mood right now. I just wanted to make note of the topic for possible discussion or for a time when my mind is more willing to think about it. If anyone has any ideas on the usage of 만나다, please post them in the comments section of this post. For example, if it were a chance meeting, as opposed to a planned meeting, would it make a difference which verb was used?
Here is a link to the Yahoo! dictionary definition of 만나다, where there are many example sentences.