Librería Samer Atenea
Librería Aciertas (Toledo)
Kálamo Books
Librería Perelló (Valencia)
Librería Elías (Asturias)
Donde los libros
Librería Kolima (Madrid)
Librería Proteo (Málaga)
The study of 'usage' has constituted a major line of second language learning research for well over two decades now. The concept of usage, however, can be defined and studied in many different ways.