The speakers are mainly discussing the rules in English language.

W: Li Hua. What are you doing this semester?
M: Oh, I’m still learning English. I have to do one more semester before I can start my real studies at the university.
W: You make it sound like prison. How are the classes?
M: They’ re all right, I guess. I don’t know. It seems like they never tell us what we really need to know.
W: What do you mean?
M: Look. When I study mathematics, for instance, we start with definitions. Then we have problems and some equations and processes to learn. You go to class, you keep up, you do the homework, and you know it. You pass exams. But English class is quite different. First of all, they don’t want to teach us all the rules. They tell us one rule. Fine. We use that rule, but soon it won’t work. It’s more complicated or there are a lot of exceptions or something. Sometimes I think the teachers don’t know the rules either.
W: But you don’t learn a language from the rules, anyway. You have to use it.
M: Yes. That’s something else they tell us. But why can’t we just go to class, study, and do our homework? That’s what I know how to do.
W: Look at this way. Can you learn to play soccer by sitting at home and reading about soccer?
M: No, of course, not. Not if you want to play well.
W: But why not? You could understand the rules of strategy, the duties of each position, and all the special situations. You have to feel the ball, practice kicking it hundreds of times, practice running down the field, moving toward the goal, and centering the ball. No one can learn that by passively studying. Learning a language is more like learning to play soccer than learning mathematics. You have to ask a lot of questions, and hear how the answers sound. You have to listen to how people indicate the important part of what they’ re saying. And then, of course, there is endless practice on all the details—speaking,"s" endings, articles…just like practice in simple dribbling and kicking.
M: But if it’s a skill like soccer, not a science, why do they teach it in schools and universities, and give you diplomas and grades?
W: That’s a good question. It is confusing, but languages are important and people do want to learn them. But the main thing is to practice the language a lot, just like soccer.
M: Maybe I’ll join a soccer team and practice English and soccer at the same time. I can talk with people before and after the practice.
W: That’s a good idea.