Number

[LUPITA]

I chose "is" of course because of "the number" as a singular reference, but can you explain why you can find for example these sentences:

"if anybody phones tell THEM to phone later"...

or what it worse for me

"the author describes themselves as a fool"

Both examples were taken from written English

[Isra]

I also voted is, because the number is singular..

[hounddog55]

Hello nicolas,

The number of students IS rising.

This is because "of students" is a prepositional phrase. It's a prepositional phrase because "of" is a preposition and it is followed by a noun. "Students" is the noun, and it is the object of the preposition "of." The prepositional phrase "of students" is modifying "number." Therefore it is simply a modifyer, and "number" is really the subject. And "number" is singular...

[pristtian]

A number of+ Plural noun + Plural Verb
The number of + Plural noun + Singular Verb

[beastmaster]

the number + singular verb
a number+ plural verb