Take a look here, Anyone and Everyone or Any One and Every One?
Student or Learner
Could anyone tell me the differences between (every thing and everything; any thing and anything)
Similarly, (some body and somebody; every body and everybody)
That grammar site does not have any page dealing with "everything" and "every thing".
Does that mean there is no difference between "everything" and "everything?
The non-compound modified pronoun any one or every one put a greater emphasis on the word one and mean "any single person or thing" and "every single person or thing."
Every thing usually goes with some other determinative/s in between. In this case, every is an indefinite adjective.
Every other thing
Every other good thing
Every single thing
Every little thing