What’s the Difference between “a Number of” and “the Number of”?

Help students figure out the correct subject–verb agreement for these confusing expressions!

A few weeks ago, someone emailed us at ESL Library to ask if the grammar on our home page was correct. In the featured lesson about protests in the Middle East, this sentence caused some confusion: “Over the past few years, there have been a growing number of both peaceful and violent protests.” The person wanted to know if “…there have been a growing number of…” was correct. Shouldn’t it be “…there has been a growing number of…”?

This is a question that commonly confuses our students! The problem is that the subject–verb agreement is different for the expressions “a number of” and “the number of.” Here’s how I usually explain it to my students:

1. “A number of” takes a plural verb

Tell your students to think of it this way: a number of means many. Becaus “many + plural noun” takes a plural verb, you would say “Many cars are on the freeway during rush hour.” Likewise, you would say “A number of cars are on the freeway during rush hour.”

The important thing to remember is that this expressions is acting like a quantifier. So even though it involves a singular noun “number,” it is serving the same role in the sentence as a quantifier such as “many,” “a lot of,” “lots of,” “hundreds of,” etc. You would say “A number of people have started the test” just like you would say “A lot of people have started the test.”

2. “The number of” takes a singular verb

Here’s where it gets even more confusing. In English, “the number of” doesn’t mean “many.” Tell your students to think of it as one number. So even though that number might be large, the purpose of this expression is to compare this one number/amount with another number/amount. For example, we would say “The number of crimes in New York has increased this year.” There might be 56 more crimes committed this year compared to last year. Another example is “The number of people who are writing the test today is larger than yesterday.” There might be 20 more people writing the test today.

For more practice, see if your students can pick out these expressions on the internet, in newspapers, or in magazines. Also, this is a very common grammar question in Part 5 of the TOEIC test, so make sure that any students you have who are preparing to write this test memorize the correct subject-verb agreement for these expressions.

I hope that clears things up for you and your students! I hope that the number of questions they have about these expressions is now zero. :)

Tanya

Source

“The number of x” takes a singular verb; “a number of x,” a plural verb.” (Einsohn, A., The Copyeditor’s Handbook, p. 344)

Examples in Use

• “Even in regular prose, a number of expressions are almost always abbreviated and may be used without first spelling them out.” (The Chicago Manual of Style, 16th ed., p. 488)

• “The article that precedes the mass noun signals whether the mass noun or the number of the noun in the prepositional phrase controls the number of the verb.” (The Chicago Manual of Style, 16th ed., p.  205)