Do you use a monolingual dictionary?

I recommend anyone learning English to buy an ENGLISH only dictionary.
The one I use and recommend is 'Oxford Essential Dictionary' WITH CD-ROM IF you don't know much English vocabulary. For more advanced learners I will find and recommend a dictionary soon.
Do not be tempted to buy the edition without the CD-ROM as the CD-ROM is essential.
The dictionary section contains the British and American English pronunciation for all the entries and a picture and video dictionary.
The exercise section contains  listening, problem words, KET and vocabulary exercises.
Finally the games section has 93 units of vocabulary with 10 words in each unit and various games to practise spelling and definitions.

The dictionary is available in Spain but it cheaper to buy online from either http://www.bookdepository.co.uk/  or http://www.play.com/
I recently ordered 7 copies of this dictionary from http://www.bookdepository.co.uk/  and the price was approximately 15€ each. Libreria Rayuela has it for 23.65€ http://www.libreriarayuela.com/

The reference number you need  is ISBN 978-0-19431722-1