For those who don't know, collective nouns are words like "family" that refer to a group of things. As I understand it, "stuff" is also a collective noun; that is confirmed by this question.
Essentially, my question is: "Can I say 'my stuff' when referring to a single item that I posses?"
If I can, does this technicality apply to other collective nouns, or just "stuff"?
If you are referring to one item in particular, 'thing' would be the word to use, as 'stuff' the noun is used only for a collection of objects.
However, were you to go upstairs and 'grab your stuff' and you came down with a bag, that looks like one thing but there are, in fact, multiple things within that bag - so using 'stuff' there is fine.
I would see no problem with using "my stuff" to refer to a single item, but I think it would be standing as an ellipsis for "any of my stuff," making it actually a partitive phrase. Presumably this same kind of elliptical partitive phrase could work with other collective nouns as well.
