The goals of a language lesson can focus on one or more of the following: Language, Ideas, Skills, or Text (Discourse).
Within each of these four areas, choices have to be made regarding the units for planning and checking the course. Often a combination of language units is used. Even if the selection of content for a course is based on topics, themes, or situations, it is useful to check to see that the language items that are covered are the most useful ones.