Is 'a number of' singular or plural?

'A number of' is plural. It means 'several' or 'many,' so it takes a plural verb (e.g., 'A number of students are absent').

Is 'the number of' singular or plural?

'The number of' is singular. It refers to a specific quantity, so it takes a singular verb (e.g., 'The number of students is increasing').

"A number of" + plural verb (are, have, were)

"The number of" + singular verb (is, has, was)

Although these phrases look similar, they have different meanings and take different verbs:

Focuses on the plural items in the group.

→ Takes a plural verb

Focuses on the quantity itself (a single number).

→ Takes a singular verb

Memory trick: "A number of" → "Are" (plural) | "The number of" → "Is" (singular)

✔A number of students are waiting outside.

✔A number of problems have been reported.

✔A number of employees were absent yesterday.

✘A number of students is waiting outside.

✔The number of students is increasing every year.

✔The number of accidents has decreased.

✔The number of applicants was surprisingly high.

✘The number of students are increasing.

Incorrect: A number of people was injured.

Correct: A number of people were injured.

Incorrect: The number of complaints are rising.

Correct: The number of complaints is rising.

Choose the correct verb:

"The number of visitors to the museum _____ (has/have) doubled this year."