How can I learn English up to a native-level?

I know when you are over certain age(critical period or turning point age - around 13), it's impossible to learn a new language at a native-level.

You can learn a new language when you get old, but you can't shake foreign accent and you still make some grammatical errors when you say something complicated.

I am a 25 year old Korean student studying in the US right now.
As an adult, how can I learn English up to a nearly-native level?
(Because I want to be a professor in the future with no foreign accent; I am taking a course from an Indian professor and she has an accent.)

I know I can not be a 100% native-like English speaker but is there any way I can speak English almost like a native speakers?

Should I stop hanging around with my Korean friends here in the US?
Should I stop visiting Korean websites or watching Korean movies here in the US?
Should I date local students(native English speakers) if possible?

Anyone can suggest some effective ways to learn a new language(English) faster and better for an adult who are already way over 13~14 years old?

Fortunately, I don't have a strong foreign accent as I am good at imitating various accents of any language. (It's a gift!)

I'm mistaken. Anyway, my analysis is what I get from my linguistics lecture. You may refer to wikipedia articles for books about language acquisition.

Getting (and maintaining) a native accent is a rather different topic. I THINK it is not the native accent that you CAN'T acquire (as seen in the testimonies of our webmasters, do check them out), but the environmental knowledge that you CAN'T EVER acquire. By that I mean: I've been never been to a Anglophone (as of now) country, and so I have virtually no knowledge of any of them, even though I know the shapes of the countries, some cultural notes offered by films, celebrities and so on, the world that I'm facing is certainly only virtual images (Plato's cave), unlike YOU who are NOW in the US.

I'm afraid I can't even speak of immersion when you are already having _immersion_. You can't live again as a baby, but on day one, every baby and every second language learner are babies of a language. Since you can already post here, I'm quite sure that you aren't already a baby, but at least a teenager of English.

And you're technically even older than me! You should be able to know what it means to "socialize" anywhere, even if you are in a foreign country. In linguistics, it's been said that affection filter (e.g. feeling shy because you think you'd make loads of mistakes) is one factor that prevents you from making progress. I'm quite sure that there have been a lot of discussions and information in this site about _learning English_.

Twenty-five years old? You think you are good at imitating accents or at least you like to do so? Your English is already decent? You are in the US?
Come on! You'll sure sound American in a few years! (or several years).

I think it is possible to be almost like a native speaker even if you start learning when you are 20, or 25, or even older... but maybe not as old as 50, but 50 is ok too if you are kind of talented. It all depends how you learn it. If you only practice one hour a week with non-natives, you are not going to learn it well even if you are 8 years old. So my advice for you is... if you are going to speak Korean 80% of the time, you are not going to improve fast. I'm not saying you should never speak Korean though.

Another thing: why can people learn a new language decently even if they are pretty old (=writing, reading) but pronunciation (=accent, speaking, listening) remains a major problem? Well, if learners used a good method to learn, that would not be a problem. You learn new words, why can't you learn new sounds? You learn grammar structures, why can't you learn to put those sounds together? Of course it is difficult, but learning how to use every word correctly and use good grammar, remembering idioms, etc., is not easy either. Yes, speaking involves physical effort at first, but so does learning to play the guitar or to touch-type.
Unfortunately, in most English courses you learn how to read and write before you can speak, no wonder most learners have strong foreign accents.

By the way, I'm not a native speaker and I still have a lot to learn, but I believe in what I said because I realize I've improved a lot, and I am still improving. And I didn't follow a good method to learn... because I learned by myself, and when you know nothing about English you can't possibly know of a good method to learn it, LOL.

I know a guy who came to the US from China (Hong Kong) in the mid 1960s, at the age of 18, and stayed here. After 40+ years of total immersion, he seems to have native-level proficiency in English.

>>>I think it is possible to be almost like a native speaker even if you start learning when you are 20, or 25, or even older... but maybe not as old as 50, but 50 is ok too if you are kind of talented.

In general, yes. Whenever we think of what others say, we think carefully, don't you? So, you'd understand. Almost all my senior relatives (the youngest in their middle age) are facing the language barrier when they end up having to stay in an Anglophone country for the rest of their lives for immigrant reasons. Guess what, I just don't know why, the Chinese, at least those in my family, tend to have been so passive about learning English. They simply don't try learn a single word; the younger ones tend to do better, but with limited education levels, they have few ideas about how to do even better.

I sort of believe that I'd give different pieces of advice to people by AGE and background. Our OP is aspiring to be a professor, so I think you should learn this language *somewhat* professionally, almost to the extent of "studying" it. Compared to your less educated counterparts in Korea (and anybody else, in general), you might find it beneficial to know more linguistic insights about a language you would want to conquer. Phonemes are one of the first steps that already sounds bewildering for MOST potential students. I'm quite sure that, if YOU can read English with much ease, you should be able to understand what everybody in this site has been talking about. Read up and you'll see how our webmasters deal with practical steps of learning.

I also sort of think, a highly-educated individual should know even more insights about how to study, well, virtually anything more effectively than their less educated counterparts, though this is in practice not always true. At least for such individuals, I think it's necessary to be able to learn through translations (the sentence method), to learn linguistics stuff when necessary (linguistics is a university subject, and not THAT hard) and, above all, sharpen their linguistics skills through interacting with (highly-educated) natives *wisely*.

I THINK education level has been one of the affective filters, that's why I demand myself much more, as a would-be highly educated person, to learn even better than an average Joe. I shall be able to discern every possible phoneme, get pronunciation (yeah, accent) right, understand every single message through immersion or, well, artificial immersion outlined in this site, and so on. These are, as I see it, some of the theoretical reasoning for someone aspiring to be a scholar to master a language, partly for his/her own very career purposes.