Pierre Urte wrote Grammaire cantabrique circa 1714, when he was exiled in England. In this article we want to prove that the main source for Urte's work was the so-called "Lily's grammar", which was the oficial grammar to learn Latin language in England from the 16th to the 19th century. The indentification of that source allows us to support the claim that Urte's grammar must be included in the tradition of language teaching, as was already pointed out by Oyharçabal (1989). In this article, we first offer a brief history of "Lily's grammar". Then, we provide some clues in order to identify the exact edition used by Urte. Finally, in the main section of the article, we confront the two grammatical works; our aim is to ensure Urte's debt to "Lily's grammar", and to show in detail the principal parts which Urte took from his source (mainly grammatical clasifications and examples).