I don't know about Korean, but Mandarin is one of the easiest languages for an English speaker to learn. I should say spoken Mandarin. Becoming literate, reading and writing, is another magnitude of difficulty. No verb endings, no gender, sounds much like English (sh, j, ch, that would be difficult for speakers of Spanish or German, for example). Tone is important, but it makes for a rather compact array of syllables. The sound approximately like "sher", depending on tone, can mean the verb to be, the number 10, or $hit, among other things. The Chinese are great jokesters, and love to mess with non-speakers of Chinese. My name in Chinese by a change in tones means "chicken taking a dump". A guy I served with named Scorby was called Szu Gou Pi, meaning dead dog fart.
Well, grass mud horse....
