Yes, I do. I have taught a teenager in junior high school. I mainly taught her grammar. I found her grammar was not very systematic. So I taught her from the grammar in words to the grammar in sentences in order to make her master the whole grammar, especially those always appeared in her exams. And during the teaching, I find the most important that it is the teacher should have a better understanding of the whole grammar and the high school English course. Besides, the teacher should pay more attention to the patience. It will make students relax when their learning and get along with the students.