Juan Kattan-Ibarra & Irene (University of the West of England, UK) Wilkie 
Modern Spanish Grammar Workbook [PDF ebook] 

Modern Spanish Grammar Workbook is an innovative book of exercises and language tasks for all learners of European or Latin American Spanish.
The book is divided into two sections:
* Section 1 provides exercises based on essential grammatical structures
* Section 2 practises everyday functions such as making introductions and expressing needs
A comprehensive answer key at the back of the book enables you to check on your progress.
Modern Spanish Grammar Workbook is ideal for all learners of European or Latin American Spanish including undergraduates taking Spanish as a major or minor part of their studies, as well as intermediate and advanced students in schools and adult education. It can be used independently or alongside Modern Spanish Grammar, also published by Routledge.