In this article the author shares two ways in which letters can be used to tell stories with different groups of learners, beginners and advanced, and in so doing develop their English language learning. Based on some theoretical concepts that connect English as a Foreign Language (EFL) learning with authenticity and communicative competence, he describes two activities he has explored with secondary school learners. The first activity is part of a lesson that involves writing letters to introduce oneself to a group of beginning learners. The second activity, targeted at advanced teenage learners, demonstrates how an "epistolary story"--a story told by a series of diary entries, letters, or other types of writing--can encourage creative writing and language improvement. This activity may be carried out during a long period of time, and its end product is the collection of epistolary stories.