Answer by Anne W Zahra:
When you study English, you have to learn a lot of words (vocabulary breadth). You also must understand how to use the words you know. (vocabulary depth).
Vocabulary breadth comes from word study. You take courses and you learn lists of words and take tests. You may buy a book or use software to study vocabulary words on your own. You should do these things because you need to know 10,000 words or more to use academic English.
Vocabulary depth comes from reading and writing with feedback. Very few English students are taught in a way that builds vocabulary depth. Materials that develop depth are uncommon. Teachers are not trained to teach this way, but this is needed, very badly needed especially if you speak Arabic, Russian, Chinese or any language very, very different from English.
A page from the Oxford series Words in Use, and a rare example of a textbook that teaches vocabulary depth. Students must learn how to use vocabulary words (vocabulary depth), but few textbooks, courses of studies or individual teachers focus on this. This is one of the major weaknesses in language teaching in general.
How do you overcome this problem?
Reading teaches you to understand the ways words are used. If you don’t read a lot you will not know how to use the words because you will not understand how they are used.
Writing in the language for a class gives you feedback— important information about what is correct and what is wrong. You need this feedback, and you must correct your mistakes and you must understand why what you wrote is a mistake. That does not happen quickly. It is not easy. It takes years.
I speak three foreign languages. I learned them mostly in school or studying them by myself. I study specific texts and I collect words from them that I don’t understand. I practice verbs a lot because these cause the most errors. I use dictionaries a lot and I use the Internet to find what words mean.