Motivation Predicts Success
Although many people believe that successful language learners have special cognitive abilities, research in second language acquisition actually tells a different story. A number of studies by R. C. Gardner and his colleagues, as well as by researchers in many parts of the world, have found that motivation is a consistently strong predictor of successful language learning. [See Masgoret and Gardner (2003) and Gardner, Tremblay, and Masgoret (1997) for reviews and analysis of this literature.]
It certainly makes sense that motivation would be associated with second language achievement since language learning requires a long-term time commitment, and motivated individuals would be more likely to devote the time required to language learning. It is also true that having a specific goal in language learning helps students focus their efforts and maintain their motivation.