|Tenses can be tricky!|
The English Tenses Practical Grammar Guide is not a book I would suggest students or teachers read from start to finish (though you certainly could). I would suggest that teachers keep this on hand to review before teaching a specific tense (or to brush up if they are teaching a new level). I would also encourage advanced students who learn well independently to consult this book to help them grapple with English tenses.
Basically, this would be a great addition for any English teacher's bookcase.
To the left you'll see a quick example of the table of contents with all of the different information is has on past tense! This repeats for the future and present tense as well.
As a paperback, this book is under $25. If you read books on your tablet, kindle or online, then you can download the Kindle version for less than $7.00! It has AT LEAST 100 pages of solid information on tenses sure to clarify this topic to anyone who reads it.
Overall I'd encourage you to add this book to your wishlist. If you do get a chance to read it, or have a different text you'd recommend let me know in the comments.