None is or none are?

Is none followed by is or are?

The answer depends on whether none refers to a count or mass noun. With the latter, none always takes a singular verb:

(1) None of the information is leaked.

When none refers to countable nouns, disagreement arises. Some grammarians prefer the singular verb, some argue for the plural verb while others contend that both are acceptable.

Always singular	None of the oranges is sweet.
Always plural	None of the oranges are sweet.
Either one	None of the oranges is sweet. None of the oranges are sweet.

Quirk et al. (214) notes that "With none, the plural verb is more frequently used than the singular, because of notional concord, even without the effect of the proximity principle.":

None (of the books) are being placed on the shelves today.

Does "more frequently used" mean the plural interpretation is "more grammatical"? Well, it's really debatable. In the absence of a definitive answer, the choice of one over the other boils down to individual style and preference.

Call me a purist, but I'm with the camp that favours the singular interpretation, equating none with not one.