Violy,

Thanks for your question. I would have to say that having students learn English only through Reading stories is not enough. I would suggest that you include writing within your strategies as a way to have students develop English Skills. A good way to use writing would be to either have the students engage in daily "interactive" journal writing where you respond to their entry, or, have the students write a short paragraph about a familiar topic, give it to another student to peer edit, make a revision based on the comments received, and then "publish their writing and then present it orally to the class. This will help students develop all of the ESL components- Listening, Speaking, Reading and Writing.
Dr. Yanni Zack