Which is the best grammar book (USA only, not UK) I need to learn and improve my English skills? I live in the USA.. Thank you.
Here's one that I use all the time - the best quick reference I've ever run into anywhere:
Amazon.com: Writer's Reference 6e & MLA Quick Reference Card: Diana Hacker, Barbara Fister: Books
...one that I use when I'm really stuck or have time to learn more:
Amazon.com: The Chicago Manual of Style: University of Chicago Press Staff: Books
...and one to reread every few years because - well, just because:
Amazon.com: The Elements of Style: 50th Anniversary Edition: William Strunk, E. B. White: Your Store