Anymore vs Any more -- What's the difference?

The difference between anymore (one word) and "any more" (two words) is described by Huddleston, Pullum, and Bauer in the Cambridge Grammar of the English Language as follows:

NOTES:
NPI: Negatively-oriented polarity-sensitive items
PPI: Positively-oriented polarity-sensitive items

anymore is an NPI: The any class of items: any, anybody, any longer, any more (AmE anymore), anyone, anything, anywhere

The correspondence between the aspectual PPIs and NPIs is illustrated in:
[26] i a. Ed still lives with us. b. Ed doesn’t live with us any more/longer.
ii a. Jill has already finished. b. Jill hasn’t finished yet.

In the aspectual sense any more is generally written anymore in AmE, and that spelling
is spreading to BrE. In positive interrogatives, some speakers allow still but not any
more longer in such examples as Does he still live with you? ~ Does he live with you
any more? A further difference is that any more/longer can be used for projection into
the future in a way that has no counterpart with still. I ’m not working here any more
is ambiguous between a present time sense (“I no longer work here” ) and a futurate
reading (“I don’t intend to continue working here”), but I ’m still working here has only
the present time interpretation.