<< I prefer learning by myself to having a teacher especially in learning English. I study English by myself. I don't go to any English school, that is I don't spend any money studying English. But that doesn't mean I study English completely by myself. I buy some English textbook and that means I am taught by the author of the textbook. Or for example, when I listening to the radio English conversation programs, I can feel as if studying with a teacher. I want to say especially in studying English, we don't have one specific teacher. Some foreigners walking on the street can be your teacher. So, I think we don't have teachers or teaching assistants when we study English. On the other hand, I need teacher when I study at my university. For me, studying at my university by myself seems almost impossible. I study medicine in my university, so I must study more than only knowledge. I can get the necessary knowledge from a textbooks, but I think doctors must have skills to cure their patients. And such skills can not be learned without the help by our teachers. On top of that we must learn large amount of knowledge, so we need to learn efficiently. We must know the essential knowledge. To get core knowledge, we must have teachers who know well about the subject such as biochemistry, anatomy, neurosurgery, and so on. I have said I don't need teachers when studying English. You may have objections to me. I must admit what I have said may be wrong in some sense. I said so because I don't need to be a professional of English, that is I don't need to earn money by my English proficiency. I want to be a surgeon, and for me, English is just a tool to do my job worldwide. So if you want to be a professional of English, you may need help by some teachers. And also what I have said seems to be true if a person is a university student or more older. I think if I asked the same question when I was a junior high school student, my answer may be different. I think high school or junior high school students need teachers whatever subjects they may be learn.