English: everyone vs every one

Tutoring English, subtleties can be important. The tutor mentions an interesting one.

The pronoun everyone means everybody, so it can only stand for people. However, every one is general purpose. Consider the two following cases:

1. She drove the large van through the dark, empty streets, dropping everyone at their homes.
2. She accidentally let go the tray of dominoes, dropping every one.

The choice of everyone vs every one allows more latitude of meaning without more explanation.

Source:

Mish, Frederick C. The Merriam-Webster Dictionary. Springfield: Merriam-Webster, 2004.