There is no absolute answer for that question. In some aspects, it is easy; in some others, it is difficult. Similarly, different people will have different answers and millions of reason why it is easy or it is difficult. Let’s divide learning English into learning different aspects of English and analyze how easy or difficult each aspect is.
-> For -> to
-> Different -> each
-> reason ->reasons.
-> divide into -> compare
For pronunciation, it is challenging to have exactly the same pronunciation as a native speaker, especially when you are old enough to have a pronunciation easily which is comprehensible for a foreigner. The difficulty for Vietnamese learners is that there are some sounds in English which are not available in Vietnamese.
Especially ( For instance) English words have stress, and if you put stress wrongly, people could misunderstand you. This feature of English is not easy to master for many Vietnamese students because we are not so familiar with what is called stress.
For grammar, it has to be said that English grammar is not that difficult as French grammar or some other languages, but it is still difficult to Vietnamese learners. It may lie in the fact (no one can deny) that English and Vietnamese belongs to totally different language families. The English language makes use of grammatical features which are not available in Vietnamese such as tenses, plural form, and word orders in noun phrases. This is the reason make difficult to Vietnamese learners. But it is also easy because we just need to be aware of those differences and learn them by memorizing one by one.
->to-> for
For vocabulary, it is difficult because there are so many multi-syllable words in English, which is not true in Vietnamese. Learning long words seem difficult but it is just the factor of time and how hard working we are and how much effort we put on it. Moreover, English uses a more or less similar alphabet to Vietnamese one. Then, we do not need time to study the alphabet again.
-> on -> into
For reading, if you have good grammar knowledge and a large vocabulary, it is not a problem. The only difficulty could just lie on the background knowledge, culture difference or logical reason difference. It is the problem of reading itself and not the problem of language.
->on -> in
For speaking, it may difficult to speak fluently and have perfect intonation as a native speaker. However, like pronunciation, it is not difficult if the goal is to communicate with others. Then we face another difficulty. Even just at comprehensible communication, it needs practice. The reason why Vietnamese cannot speak English even after many years of study is that they do not an environment to practice. They are shy to speak out because they are afraid that they will make mistakes and others will laugh at them. Just be bold and practice hard, speaking English becomes easy.
For listening, once again the difficulty lies in the fact that we do not have an English speaking environment, so we can practice listening to it on daily life basis. But with the development of communications, we can create for ourselves such environment by listening to English songs, English radio programs or by watching English TV programs, English movies and so on.
For writing, like reading, good grammar, and good vocabulary ensure more than 50% chance of being a successful writer. The rest lies on how good your idea is and how good you are at playing with words.
In conclusion, we can say English is difficult but it is not so difficult to be impossible to obtain. If you have great incentive to learn it, English become really easy and relaxing to learn.
Theo mình thấy thì bạn dùng hơi nhiều từ difficult