My favorite subject is English,because it’s useful and interesting. My English teacher is Mr. Li. I like him very much. He is really funny, and he is the tallest teacher in my school. But my sister don’t like English, she thinks English is the most boring subject of all. Although she doesn’t like English, she likes our English teacher for his funny and kindness. Her favorite subject is math. She is interested in these numbers. However, I don't like math. I think math is the most difficult subject of all. My sister often helps me in learning math. So do I. I help her to learn English. 
Why does the author like English and the English teacher? 
Do you like English? Why?