This article sums up theory about language biographies and their existing applications within the field of linguistics. Being a less used (any maybe less known) method within Hispanic linguistics, the goal of this article is to give an overview over the theory of language biographies and its existing applications within linguistics. The article is based on works of German and English language, which have been as well as the author’s experiences applying this method in his own research. It is intended as a starting point and incentive to interested scholars within Hispanic linguistics.