The Handy Guide to New Testament Greek: Grammar, Syntax, and Diagramming by Douglas Huffman is an extremely helpful little book for second-year Greek students. Though it is not intended to replace grammars such as Wallace, it does serve as a helpful refresher for pastors on the go, teachers who are super busy and seminarians who just want to find a basic grammatical principle quick.
In this book you will find charts, basic grammatical discussions, and even an entire section on how to diagram (complete with an example of 1 Peter 1:3-9)! It is amazing how much is packed into a book of only 106 pages!
I really wish I had had this helpful tool when I was taking Greek. It is realistic (it understands pastors do not have a ton of time) yet it also encourages pastors to not quit. Any book that helps make Greek accessible to busy students/pastors everywhere. I wholeheartedly recommend this handy book!
*Thanks to Kregel Academic for providing a free review copy of this book in exchange for a fair review*