confusion

Whenever I watched an American movie, I often heard this words “I got it, I got it” which an actor used. So, I thought I would say that word some day. One day, I visited my roommate grandmother’s house. I used to talk with her grandmother after dinner. Before the day of thanksgiving, she suggested, “Why don’t you go to the church tomorrow? You can know catholic church. ” And I answered, “ I got it!” After that, she started laughing. I was embarrassed because I didn’t know why she laughed. After laughing, she told me that people usually do not use that words when they talk with older person. And she explained that “I got it” is slang. Some times, it is hard to know which is slang or not. Because I used to hang out with peer, I don’t know how I take care of talking with older person in English. Fortunately, she seemed to see me cute. And I realized that I had to study English more and more. International students who live in America can face some problems because of a misunderstanding. It could be serious situation unless we do not solve this problem. But if we try to know what difference is and talk our opinion frankly, it will not face serious situation. I think it is good chance to know American culture and people more. Therefore, I will make a constant effort to say the other words to not have misunderstanding. That’s why I came here. ^^