The Best Ways for Native Koreans To Learn English Quickly (Update1)

As a person that knows both Korean and English, I know very well the differences between the languages.  Here are the top ten ways (Americans like to use the idea of "top ten" lists) to improve your English language skills.  These are areas which pose Korean native speakers particular trouble in learning English.

Before reading the tips below, be sure to look at the following post: 
"English is not difficult...when compared to Korean.  Here's Why"

Here are a few helpful tips:
1.  Do not emphasize vocabulary.  Here is an unwritten, and yet true, fact:  you probably know more words in English than native speakers, including the teachers at your hagwons.  Books in Korea are written to repetitively memorize.  However, the lists and books that I have seen in Korea are excessive.  Please note:  this does not apply if you are studying for the SAT or college entrance exams and want to enter Ivy League universities.  In English, on a "daily" basis, the actual number of English words actually used is far fewer than the number of words that is used in Korean.  In addition, there are usually very few new terms/words in English, especially in academic settings.  In Korea, the amount of slang that is used, and the amount of slang which is created, changes occur very rapidly (making Korean very difficult for a foreigner to learn).

2.  Spend time on the three most difficult words (for Koreans) in the English Language:  a, an, and the  This is a difficult matter for all Koreans, because there is no such thing as an article (which is what the words a, an, and the are).  You need to be able to tell the difference among them.  I have read published newspaper articles by Korean Law Ph.D's that have made errors with these three words, so please know that it is indeed difficult for native Korean speakers.

3.  Number agreement is more difficult in English than in Korean. A singular noun must be used with a singular verb, and plural noun must be used with a plural verb.

4.  Verb tense is more complicated in English than in Korean.  You should practice these four forms:  future, present, past, and past perfective. 
For example, the verb "swim (수영)" for a singular noun has the following forms:  will swim, is swimming, swam, and swum.  The issue here is that for plural nouns, sometimes the same verb has the same form, and sometimes it does not. 
For example, the plural form of the verb "swim" has the following forms:  will swim, are swimming, swam and swum.

5.  Accentuation and length of syllables.  In English, the accent is not always on the first syllable.  One very good thing about Korean is that the accent is always on the first syllable.  In addition, unless it is used as slang or for a very particular emphasis, Korean syllables have equal length.  This is not the case in English.  Practicing this will greatly help you to be understood by listeners.

6.  Ignore the Konglish pronunciation.  This is difficult because now there are so many words written in Hangul which are actually English words.  For example, "헤어 케어" is hair care which is now another way of saying 미용실.  The problem that this causes is that there is no sound of the letter "r" in 헤어 케어.  One of the sounds that you will hear most often in English is..."r."  If anything, native Koreans should try to never skip the sound "r" in a word.  As I have mentioned in this post, the sound of the letter "r" is usually the longest sound in any word.   When possible, native Korean speakers should try to pronounce Konglish words as they are supposed to be pronounced in English.

7.  Shorter, simpler sentences are better than long, incorrect sentences.  It is natural for someone to try to display his/her command of English by creating long, complicated sentences.  The problem with this approach is that if there is a single error, then a native English speaker may get distracted.  Practice writing clearly first, and then you can write longer, more complicated sentences.  This is even more important in speaking.

8.  Using Twitter and Facebook doesn't mean that you should make errors in the interest of brevity.  In English, Twitter posts are limited to 140 characters.  It is a very good place to establish bad habits.  It is better to write short sentences which have no grammatical errors.

9.  Read the 영어 Hint of the Day: Collection page frequently.  If you are a Business English student, then specific Business English advice can be found here.

I will continue to add to this list.
Please feel free to comment and post issue. opinions, or questions here.