Dictionaries attempt to explain a difference, but common language seems to prefer the single word, unless interrupted by something like “single” or in the phrase “each and every thing.”
As two words, “every thing” counts each one individually, as in “every single thing” or “each and every thing.”
As one word, “everything” refers to the entire collection in its wholeness. It refers to all of the things in that one word.
In choosing one or the other, the writer should consider the message to be conveyed, the difference being if the individuals matter.
- As I looked around my teenager’s room, every thing she owned was put in its proper place or was buried in a drawer where I could not see it. I even looked under her bed.
- (“Every thing” = each individual item)
- I couldn’t believe it. Everything I had taught her had now been absorbed.
- (“Everything” = the totality of what I had taught her)
- Do you remember every thing your mother said? I don’t.
- (“Every thing” = each individual teaching)
- But sooner or later, everything clicked into place.
- (“Everything” = the totality, it all clicked)