"A Number Of" vs "The Number Of" Agreement in Technical English
5 exercises — practise verb agreement with "a number of" (plural) versus "the number of" (singular).
0 / 5 completed
1 / 5
Which sentence correctly uses plural agreement after "a number of"?
"A number of requests are timing out during the peak hour" is correct: "a number of" means "several" and always takes a plural verb, regardless of the singular word "number". Option B incorrectly uses singular "is". Option C wrongly uses the singular noun "request" instead of the plural. Option D mixes past "was" with the present adverb "currently", and also misuses singular agreement.
2 / 5
Choose the sentence that correctly uses singular agreement after "the number of".
"The number of open tickets has doubled since the last sprint" is correct: "the number of" refers to the count itself, a singular concept, so it takes singular "has" even though "tickets" is plural. Option B incorrectly uses plural "have". Option C wrongly makes "ticket" singular, though the counted noun should stay plural. Option D scrambles the auxiliary and main verb order.
3 / 5
Select the sentence that correctly contrasts both phrases in the same status update.
"A number of services are degraded, and the number of affected regions is currently three" is correct: "a number of" takes the plural "are", while "the number of" takes the singular "is", exactly as each phrase requires. Option B reverses both agreements. Option C incorrectly makes the second clause plural. Option D wrongly singularizes the counted nouns "service" and "region".
4 / 5
Which sentence correctly keeps singular agreement with "the number of" even when a long noun phrase intervenes before the verb?
"The number of unresolved critical security vulnerabilities in the dependency tree is a growing concern" is correct: the verb must still agree with "the number", not with the nearer plural noun "vulnerabilities", regardless of how long the intervening phrase is. Option B incorrectly agrees with the nearby plural noun instead of "number". Option C uses past tense "were", inconsistent with the ongoing present concern. Option D uses the ungrammatical bare form "be".
5 / 5
Choose the sentence that correctly uses "a number of" as a quantifier meaning "several", not as a literal reference to a specific numeric value.
"A number of edge cases were missed during the initial test pass" is correct: "a number of" functions as a plural quantifier meaning "several", correctly paired with plural "were" and the plural noun "edge cases". Option B incorrectly uses singular "was". Option C swaps in "the number of", which would require singular agreement and a different meaning (a specific count). Option D wrongly uses the singular noun "edge case".