Two commonly confused words are forward and foreword. Forward is a directional term meaning “near, being at” or “moving, tending, or leading toward a position” (Merriam Webster Online). Foreword is a section of a book for “prefatory comments … especially when written by someone other than the author” (Merriam Webster Online). For example:
As we move forward in this project …
As the author mentioned in the foreword to her volume ….
A useful device for remembering how to spell foreword is to think of its constituent parts: fore (near the front) + word (something written).
For additional commonly confused terms and guidelines for proper word usage, see CMS §5.220.