Can Not vs. Cannot: Both Are Acceptable

Kevin writes in:

Hi Snarky. I took a picture of this bumper sticker yesterday because it looked strange to me. Is cannot a word? I always write can not.

I'm with you, Kevin. Cannot has always looked funny to me, too, but it's a perfectly legitimate variation of can not. In fact, you see cannot more often than can not.

Quick rules:

• Cannot and can not (and can't, for that matter) are interchangeable.
• Consider using can not when you want to be more emphatic. No, I can not let you borrow my new iPhone.