Lessons are given to students by teachers with, on the one hand, the aim of imparting knowledge and on the other hand, providing a space in which students can practise their language skills in a non-threatening setting. Beyond this it is difficult to be more explicit as so many factors affect class content. At one extreme teachers follow a highly structured lesson plan describing each stage of the lesson in sequence; at the other teachers on the "Dogme" end of the spectrum may well eschew such documents and simply see what the world brings. Naturally the majority of teachers will be somewhere in between.
Factors which will affect the nature of the class include the following basic concepts:
Size of the class
Classes range in size from a single individual (one-to-one teaching) to many dozens or more. As a rule, the larger the class the more formal and structured it may need to be.
Age of the students
Teachers may find themselves in front of young children, teenagers or adults. Clearly the class given will change for each age group.
More formalised presentations may be necessary for students who have a lower level of English.
Aims of the class
Ideally the students and the teacher will have the same objective, be it to improve fluency, study for an exam, or finish a coursebook. These long-term objectives will necessarily have an impact on each individual lesson.