Usage tip: everyday vs. every day

This one crops up so often, it's practically an everyday occurrence. (ha, ha, ha...sorry.)

Here's the difference between everyday and every day:

Everyday is an adjective.
Every day is an adverb.

But that doesn't really matter. You want to know how to use them correctly, right? Here's a handy rule of thumb:

If you can replace the term in your sentence with occasional or frequent or any other adjective and have the sentence still make grammatical sense, chances are you should be using everyday. If you can replace the term with Tuesdays or sometimes, you should probably be using every day.

For example:

WRONG
This shampoo is best for every day use.
Everyday, I walk my dog.
People should try to exercise everyday.
Luckily, loud street arguments are not an every day occurrence in my neighborhood.

CORRECT
You can use this shampoo every day.
Some trainers say you should run every day, but I think that's too much.
He's trying to prove that he's an everyday guy.
Let's try to make laughter an everyday event.