Check out Be-verb Bumper Stickers Make a Comeback by Marcia Riefer Johnston. Here is an excerpt:
A car pulled up next to my Prius at a stoplight in downtown Portland. The driver opened her window and asked, “What does your bumper sticker mean?” Through my passenger window, I told her that it means to look for verbs like “is” and “were” and “are,” and then consider how you…
The full article is available here.