I become more and more convinced that it is not necessarily an advantage, for Korean learners of English, that the Korean language (South Korean, anyway) has been so welcoming of English vocabulary over the last half-century. In fact, it creates some serious problems. Here's why.
Korean phonology allows far fewer consonant clusters than English does, and in general, vowel and consonant inventories are radically different between the two languages, too. Therefore, when Korean borrows an English word, it messes with its native phonology substantially to make it "fit," or nativize it. The main thing that happens is that "epenthetic" vowels are inserted between consonants that aren't allowed to follow each other in Korean, or at the end of English words that end in consonants where Korean doesn't allow such a consonant ending.
A notorious example: printer -> 프린트 (REV peurinteo IPA [pɯrintʌ]). The main Korean epenthetic vowel used is 으 [ɯ], which is basically the Korean functional equivalent of the English schwa [ə]. Because of this, the problem is exacerbated by the fact that Korean speakers develop the mistaken belief that [ɯ] is a common English sound, when, in fact, it not only doesn't exist in English but is a freaky, difficult, weird-sounding vowel for English speakers.
The problem is that Koreans then internalize a false rule, which is that this sort of vowel epenthesis is the "right" way to pronounce English words. I've had kids literally argue with me, passionately, in class that "hadeu" (IPA [hadɯ]) was the "right" pronunciation of the word "hard," for example. The reasoning is basically that, if these thousands of borrowings from English into Korean are English words, after all, how could Koreans be saying them all wrong? It's naive "folk" linguistics, but it becomes a huge battle in the classroom.
Worse… in some kids, whose parents or former teachers thought they were doing them a favor by transcribing their English lessons into hangeul (Korean alphabet), the problem becomes insanely worse, so that they will utter whole sentences, verily, entire speeches, in "hangeulized" English. I had two students do this today. I wanted to cry. How can I help them, when they argue that "del ijeu noting rongeu wideu ma-i peurononshieishon" (there is nothing wrong with my pronunciation)?
Sigh.