In my first book – Inglês na Ponta da Língua – I state that vocabulary is the most important thing when learning a second/foreign language. The thing is: you can learn, if possible, every single English grammar rule and exception; however if you don’t have a good vocabulary, you won’t be able to communicate properly and fluently.
I usually tell English Language Students as well as Teachers that learning vocabulary is not about putting words into a list and trying to memorize them. I am pretty sure that you can make a list of ten to twenty words, set the commitment to memorize them and everything; however, if you don’t know how to make real use of these words [how they combine with other words] everything will be useless.
Nowadays, ELT/ESL Professionals, Methodologists and even Grammarians agree that what really matters is usage; that is, how a certain word is really used by an English language native speaker.
Let’s take the word “wish” as an example. You can learn its meaning in Portuguese, you can even learn a couple of interesting grammatical things here and there [it's a verb, a noun, etc]. The real questions, however, are: can you really use the word “wish” the way a native speaker really does? Can you use it naturally? Do you know the words that it collocates with [the collocations]? What about the grammar that involves it? How is it really used with other words? What some of the common expressions? And so on!
Learning 20 words [or even more] a day is not, in my opinion, the ideal thing to improve your vocabulary. Learning rare and difficult words like ‘fathom‘, ‘anew‘, ‘abet‘, ‘waif‘, ‘timorous‘, etc is not useful either. Think about it: what’s the point in learning words which are rarely used in everyday conversation? Why do you have to waste your time on that?
The truth is that as an English language Learner, you should pay closer attention to the way words are really used, collocations, the grammar that involves the word and that sort of thing. Then, you may ask: “Denilso, English Language has more than 1 million words; so, what words should I pay attention to?”.
The short answer to this question is: “Pay attention to words which are really used in English Language, specially those with a lot of meanings and which are part of the 200 most used words in everyday conversation and texts“. These words are of paramount importance in everyday use of English Language. The sooner you get used to how they are used, the better your vocabulary and communication skill will get.
Examples of such words are: get, take, look, back, do, have, way, wish, just, only, mean, know, like, want, very and a few others. Think about expressions, collocations, the grammar and everything else that goes with these words. When reading a text or checking a dictionary pay attention to the way they are used. Spend your time investigating them! Do not spend your time trying to memorize lists of [rare] words in an isolated way.
Your learning has to be useful and significant to yourself! So, how about making it simpler and painless?!