If you study in Korea, the first thing you will want to do is to study Korean because you have to be at least level 3 in Korean to be admitted to a university there as an undergraduate. I recommend you begin by going to a language school. There are two that are really good and are not as expensive as going to school in America. My daughter attended the Korean language school at Seoul National University, and it is excellent! If you take all the classes there, at the very end, you can be considered to be a Korean teacher. A friend of ours went to Yonsei University’s language school, and it is also excellent. Seoul National University concentrates more on speaking, and Yonsei University concentrates more on grammar.
If you already have a B. A. degree, there are M. A. degrees taught all in English. I don’t know where they all are, but if you got Korea Christian University, they have a Masters in Theology taught all in English. They have students from all over the world studying in their masters program. You can also get a Theology doctorate there in the English language. Their professors are Korean, but many went to school in America and have American citizenship. Sometimes, they have an American professor there who helps in these degrees too. If they have an American, they are usually on the graduate committee to test the degree candidates so they can finally receive their degrees. This university used to send me graduate students for me to help them with their English and their theological ideas in their thesis because that is where I taught, but I was an English professor who has a minor in Bible, and I never sat on the committee for the students to get Theology degrees.
I have looked into higher degrees at Women’s Ewha University in English, and they study English and read English works of literature, but the classes are taught in Korean. There is a university over in Dongdemun where a friend of mine got a masters in Business taught in English. Another friend of mine went for a masters in English at another university, but he had to have the Korean language requirement there because all the classes were taught in Korean, and his classes were tedious grammar classes.
I hope this helps people wanting to study in Korea make the best decisions about how to go about it. I really recommend people study Korean if they want to study in Korea. You can get into very few universities there without knowing Korean. The best option is to begin by attending a language school. You will be building credit hours in Korean if you do it that can be used in other countries, but not in Korea.