These self-study workbooks deal with some of the most difficult aspects of Spanish. This book belongs to the collection Practica tu espanol that shows the most difficult aspects of Spanish as a second language. An answer key is included. Grammatical and lexical contents are explained (in Spanish) accompanied by abundant examples. 2007. The series consists of: Los tiempos de passado (level B1); El lexico de los negocios (level B2); Practica la conjugacion (level A10); El subjuntivo (level B1); Las preposiciones (level B1); Las expresiones coloquiales (level B1); Ejercicios de pronunciacion (level B1 - comes with its own CD); Ser y estar (level B1); and, Marcadores del discurso (level C1) and Ortografia (levels A2-B1).