Matsutani-san wrote in his diary that he thinks the most efficient way to memorize English words is by using a word book – he memorized 2000 words in a month using this method! But he said it might be boring to some people and asked my opinion on the best way to memorize words. I’ve been thinking about it and my answer is a question: How did you learn Japanese words?
Of course, the answer is easy: you’re Japanese and Japanese is your native language. But if you think about it carefully, the reason why you know a lot of Japanese words is because since your were a baby you have been hearing Japanese words and they got stuck in your head, you see and read Japanese words around you and you remember them when you see them again, and you use these words when you speak until they become a part of your vocabulary.
If you want to learn and remember English words, I think the best way is doing the same thing: surround yourself with English. Read, listen, think, and speak. It will be difficult in the beginning. You will forget many words you just learned, and when you try to use them they will feel unfamiliar in your mouth. But if you keep using these words, if you think about them, and if you keep reading to remember them, little by little, they will widen your vocabulary.
This method is not going to teach you 2000 words in a month, but it will give you tiny English friends you can call to help you when you need to express yourself. And when they come out, it will be smooth, familiar, and natural. Learning thousands of words is good, but I think learning some words and being able to use them when you need them is much better.