SVA Rule #12. 

Although the expression ‘a number’ is strictly singular, the phrase ‘a number of’ is used with plural nouns (as what grammarians call a determiner (or determiner)). The verb should therefore be plural. However, this is not the case with ‘the number’, which is still singular:

 A number of people are waiting for the bus.

The number of people here has increased since this morning.

 Example #24. 

Find the main subject and verb.

There are a number of important announcements in the bulletin.

Here is the number of milkshakes you requested.

 

Click to see the correct answer There are a number of important announcements in the bulletin. Here is the number of milkshakes you requested.

 

 Example #25. 

A number of dog in our neighborhood actually like the mailman.

  1. NO CHANGE
  2. A number of dogs in our neighborhood actually likes the mailman.
  3. A number of dogs in our neighborhood actually like the mailman.
  4. A number of dog in our neighborhood actually likes the mailman.

 

Click to see the correct answer The correct answer is choice C.

 

 Example #26. 

The number of dogs in our neighborhood has grown over the past several years.

  1. NO CHANGE
  2. The number of dog in our neighborhood has 
  3. The number of dog in our neighborhood have 
  4. The number of dogs in our neighborhood have

 

Click to see the correct answer The correct answer is choice A.