Can Not versus Cannot

These terms have confused me for the ages, when to use cannot or when to use can not. The Shrunk and White’s “Elements of Style,” and various other style guides make this discussion as clear as mud. So allow me to clear the waters a bit.

My best source for information comes from the Merriam-Webster Dictionary. Yes, I still use the paper version. Second is Grammarly.com, but you still may wish to edit the corrections it provides.

Using cannot or can not are acceptable in most cases, though cannot is the more common spelling. Yet there is a difference.

Cannot is used when someone or something is unable to do something. For example: He cannot lift the weight; or She cannot come to work today.

Can not should be used when not is the is part of a larger sentence structure. He can not decide to order the steak or fish. She can not decide if she wanted to go the beach or mountains for spring break.

Then we get to can’t. According to Merriam-Webster, can’t can be substituted in either case.

That should have cleared the waters. I hope.