What is the best English grammar book you know?
I'm Renan, from Brazil.
Specifying my question: what is the easiest grammar book that comes to mind? Which is the most complex and in-depth? Do you know any very good punctuation marks?
If you can mention the country and the name of the author will help a lot too. My intention is to know your language through the best reference in your country... as much as I researched about it... that doubt always hits, always.
Thank you for your attention!