How to Learn Vocabulary

" vocabulary is tough because you need words to understand people," he says. "People use a lot of words I don't know, so I don't really know what they're saying." And then there's the problem when you're speaking and trying to say some idea or talk about something. But you can't remember or you don't know the words in English. How do I say this? You don't have the words. So it becomes difficult to say what you want to say, to communicate your idea or your topic".