Learners can grasp the general meaning of many forms they have not learned completely. Students needed to be challenged; otherwise, they move lose their motivation. The students can prepare some real or authentic materials outside the classroom with the help of the teachers. The students are supposed to cope with real language, not just artificial classroom language. If the teachers want the students to learn a new structure they have not mastered, they can use “narrow-focus” materials which isolate the new form in a context where other things are seemed easily.