The focus of a CBI lesson is on the topic or subject matter. During the lesson students are focused on learning about something. This could be anything that interests them from a serious science subject to their favourite pop star or even a topical news story or film. They learn about this subject using the language they are trying to learn, rather than their native language, as a tool for developing knowledge and so they develop their linguistic ability in the target language. This is thought to be a more natural way of developing language ability and one that corresponds more to the way we originally learn our first language.