It is well-known that the knowledge of a dominated language does not have automatically as a corollary its use in the everyday life, out of the place of learning. There is a more or less large gap between the knowledge and the use of the minority language. In the first time, this variation is illustrated through various investigations which were carried out in Basque Country where the Basque language teaching largely developed during these thirty last years, especially in Basque Country of Spain (Hegoaldea or Southern Basque Country). In the second time, one lists the various factors which induce this variation, factors which make that a minority speaker of language uses or not this language, so then working out the draft of a typology of those. The taking into account will be dynamic since the impact of these factors evolves/moves constantly in a given context with the statute of the considered language, the place of this language in the society and with the situation of the speaker himself. One concludes the reflection by proposing a diagram of these factors in the form of concentric circles, with in the center the potential speaker.