Early years teachers instruct students, primarily young children, in basic subjects and creative play with the aim of developing their social and intellectual skills in an informal way in preparation for future formal learning. They create lesson plans, possibly in accordance with a fixed curriculum, for an entire class or smaller groups and test the students on the content. These lesson plans, based on basic subjects, can include the instruction of number, letter, and colour recognition, days of the week, categorisation of animals and transport vehicles etc. Early years teachers also supervise students outside the classroom on school grounds and enforce rules of behaviour there as well.