Links in this essay will take you to information about the usage experts and their work. Numbers in parentheses are page references in the sources.
If you were taught that the word none is always singular, you were taught a half-truth. Yes, none can be singular, but it can be plural as well. Respected writers have been using the word both ways for a very long time.
Those who once argued that none must be singular claimed that it meant "not a single one." In fact, it quite often means "not any." Writers are more or less free to decide which meaning is appropriate in their context. Advice given by Richard Lederer and Richard Dowis is typical: "Consider none as singular when you want to emphasize a single entity in a group. Consider it plural when you want to emphasize more than one" (98). For Lederer and Dowis, both of these sentences are acceptable:
None of us is going to the party.
None of us are going to the party.
According to Wilson Follett, insisting that none must always be singular can lead to absurdity. Consider his example: None of these authorities agrees with one another. As Follett says, "Here none is trying to be both singular and plural at the same time" (227). Logic requires none to be plural:
None of these authorities agree with one another.
There is one situation in which none must be singular: whenever it means "no amount" or "no part." Wilson Follett gives the following examples:
None of the debris has been cleared away.
None of our skepticism is allayed by such protestations. (228)
Patricia O'Conner offers a practical test for deciding how to treat none. If your meaning is "none of them," treat the word as plural; if it is "none of it," treat it as singular:
None of the fans are fighting. None [of them] are excited enough.
None of the bout was seen in Pittsburgh. None [of it] was broadcast. (24)
Conclusion: Treat none as singular or plural depending on your intended meaning.
Source: Hacker Handbooks (Boston: Bedford, 2013).