It's a billboard custom-tailored to grammar buffs. "Every day we help people get back to their everyday," proclaims the ad for Keck Medical Center of USC. In that single sentence, the copy writer does more to help people with grammar than I probably will in this whole column. But I'll give it a long-winded shot anyway.
The best thing about this line of marketing copy, grammar-wise at least, is that it succinctly illustrates something far too few people know — that both every day and everyday are valid forms. Plus, it deftly illustrates proper use of each while sneaking in lessons in advanced grammar concepts.
Not that motorists merging onto the Arroyo Seco Parkway to downtown Los Angeles are hitting the brakes to get a language lesson. But anyone who bothers to read all 10 words is likely to register that "every day" and "everyday" both have their place — or at least wonder whether a proofreader made a whopper of a mistake.