A: Ralph, do me a favor, will you?
            B: That all depends on what it is.
            A: This is the proble, I'm still having trouble with my English. The
            instructor¹ suggests that I ask an American to help me by telling me
            how he says the things I say which just aren't English. I wanted you
            to be the American.
            B: What good'll it do? You never speak English unless you absolutely
            have to. I'll help you if you promise to speak noting but English
            all the time.
            A: All right. Maybe I'll do that. It's the only way I'll be able to
            learn English fast enough, I guess.

            Notes
            What good'll it do? - it will be useless
            Unless you absolutely have to… 除了你非…不可
            Make a bargain with sb. 同…约定

            A：拉尔夫，帮我一个忙，好吗？
            B：这要看帮什么忙。
            A：我有个困难。我的英语仍然遇到麻烦。老师建议我请一位美国人帮助，要他告诉我，我说的那些根本不像英语的话应当怎样说。我想要你做这个美国人。
            B：这有什么用？你除了非说不可的时候，你从来不说英语。好吧！我跟你达成一个协议：如果你保证在任何时候除了英语外什么也不说，我就帮助你。
            A：好吧，也许我能办得到。我想这是我能迅速学会英语的唯一方法