In terms of actually teaching register, you may want to try the following exercise. The concept is simple and you can easily modify it and apply it to your learners’ needs, abilities and circumstances. Here, I will present a simple, generic version of the task:
Ask your students to produce the following three texts:
• A facebook message to your best friend, letting him/her know that you can’t make it to their birthday party on Saturday;
• An email reply to a colleague, politely declining their invitation to a restaurant next week;
• A formal email reply to your supervisor at work, letting him know that you won’t be able to attend next week’s training seminar, as you have already arranged a doctor’s appointment, which cannot be rescheduled.
(50-80 words per piece)
The purpose of this introductory exercise is to highlight the significance of register on the one hand and to give your learners the opportunity to practise on the other. What is effectively asked of them is to reproduce the exact same rather simple message – ‘I can’t make it to… on…’ – in three substantially different ways. Your learners will naturally appreciate the necessity of using different modes of address, lexis, organisational patterns, and structures in each of the three texts. They may not be able to do so successfully at first, but the primary objective of this exercise is to make them interested in register by appreciating its use and applications. As a result, when you proceed to teaching them alternative means of expressing themselves, you will be directly addressing a need that your learners have already become aware of.
Please note that register must be linked to genre, medium and audience, so that your students are able to fully appreciate it in its entirety. As a final piece of advice, I would strongly encourage you to take your learners’ situation into consideration when introducing them to such concepts. Although I do not consider register to be a particularly challenging or difficult topic to teach, I do recognize the danger of it becoming a far too abstract concept to teach, especially when it comes to young learners. You may want to adjust, then, the different levels of formality you intend to introduce to them, to their circumstances, so that register becomes tangible and, as a result, transferable.