Most authors agree that learning a language can be optimized through the use of strategies. However, there is no agreement on what exactly strategies are and what characteristics they have. The lack of clarity or the generalization in many of the definitions cause some problems in the empirical field and the measurements performed tend to present weak psychometric properties. This article presents a critical analysis of different definitions and a search for patterns and etymological tracking, in order to specify the attributes underlying the concept of language learning strategy. The new proposed definition establishes a clear difference between what is strategic and what is not, based on the notion of efficacy and efficiency. Furthermore,...