I saw this in an email message from a personnel department.

Problem:
The space between “every” and “one” does not belong.

Explanation:
The complete sentence in the email message was “The supervisors will hold a short meeting to advise every one of housekeeping items and scheduling information.”

“Every one” — with a space between “every” and “one” — is a noun phrase that means each person or thing.

An example of the correct use of “every one” (with the space) is “Every one of the plants had turned brown.”

“Everyone” — without the space — is a pronoun that means everybody in a group.

An example of the correct use of “everyone” (without the space) is “Everyone likes an end-of-year bonus.”

Solution:
“… to advise everyone of housekeeping items …”