Which is grammatically correct? (And why?)
- (a) "There are an odd number of items in the box."
- (b) "There is an odd number of items in the box."
Which is grammatically correct? (And why?)
It depends on the focus of your interest...
An odd number of socks means that one sock at least has gone missing.
An odd number of socks have ended up in my sock drawer.
You want the verb to agree with "number," not "items," so the answer is (b).
It helps to turn the sentence around. "An odd number [of items] is in the box."
Number is actually the subject of the sentence, whereas "items" is the object of a preposition and does not get to determine whether verb is single or plural, "is" or "are."
"Lot" can be singular, as in an auction, or plural. The presence of a plural noun (items) wants to push it toward plural, but my point is to remember that the subject of the sentence, not a prepositional object, determines the tense of the verb.
– Chas S. Clifton Mar 15 '17 at 21:01