I won’t say that it is achievable to learn a language in one day. It doesn’t sound realistic for me today.
Don’t give up now! Believe in your dreams and try! One day it may be possible, I think. Besides, I always believe in the capacities of my students (or everyone else)! So, you have my mental support and belief: you can do it.
Maybe for you, it’s possible in more ways than for me as I’m already walking on my own and a little different from yours one English-learning path.
In 24 hours you may force yourself to study the most used words plus the most important ones. You also can easily review them to remember better the new and complicated lexis.
I’ve tried, and there are a lot of techniques of learning new words in short periods. For example, they train people to learn 100 words per hour. As soon as you accept this possibility, you also will repeat this experience. When you master each 100 words per hour, you’ll be able to learn more and more words per hour. This is not a crazy fantasy, but an experience of real people. Just give it a try!
As for me, I teach English in 30 days or one month. You should pay attention that my teaching method supposes to spend about 2–3 hours per day for learning. This activity includes a lot of work in class and at home as homework, watching, listening, speaking and writing in addition to the classwork. If a student is devoted to his studies enough he/she learns faster.
I remember one student who wanted to enter the University where they teach in English. He did everything he could to succeed and to finally enrolled in that University! Now he sends me the pictures of his new friends, new house, and shares his success in studies with me. At this moment I should cry, but I can’t as I feel triumphal since it’s my victory too.
The principal point here is to use the information that you’ve learned at once and several (not more than a thousand!) times before the next class.
If you can easily remember new words and if you’re not shy to make lots of mistakes, it is possible for you to try to learn English in a week. Hey, this language is easier than Latin, French, Russian or Spanish! You already know some English words if you are at least ten years old and live in a country where people have an Internet access and have their computers. The two terms we met are English ones: computer and the Internet.
Go on: you can do it, you can learn a new language! And you will do it as soon as you make this decision!