Study abroad

Hi!! I'm a college student in Japan. I am majoring in English. I always study English literature, grammer and listening, but I want to study more!! Recently, I am interested in studying abroad. I want to talk with English speakers. I also want to know what they think. I think studying abroad is good for students who want to improve their English skills. However, I have a big problem. That's money. It costs much money to study abroad, but I'm not rich. So I am going to take part in the short-term study abroad, like summer vacation. Then I have a question. Can I progress in my English ability in only a month? If I can't get certain result, I think the short-term study abroad is in vain. I f so, I don't join the plan. What do you think about it? Can I improve my English skill in only a month?