Learning a new language is largely about learning how to speak and listen in that language. Every language has its own unique features, and English is no exception. The videos and exercises that are linked from here are designed to help you understand what you hear, and to practice the sounds of English so that other people can understand you.
Like with just about everything else, practice is essential to improving your oral and aural (fancy words for spoken and hear) English. In addition to what you learn here, make sure you find or create opportunities to practice listening and speaking English.