NUMBER with 'a' or 'the'

A NUMBER OF
- 'A number of' is used in the same as 'some', ‘several’ or 'many'.
- 'A number of’ does not refer to a precise figure, but to a certain number, more than one, in the presence of other people or things.
- 'A number of’ is used with a plural verb :
Example: « A number of passengers were injured. »

THE NUMBER OF
- ‘The number of’ refers to an exact figure or specific number.
- ‘The number of’ is followed by a singular verb :
Example: « The number of seats reserved is 250. »

EXAMPLES:
• The number of online customers is increasing.
• A number of customers are complaining about slow delivery.
• The number of passengers is limited to 50.
• A number of people are waiting for the bus.
• The number of contaminations is increasing.
• A number of those contaminated are in intensive care.
• The number of road accidents is causing great concern.
• A (large) number of accidents are due to careless driving.
• The number of guests at the wedding was quite small.
• A number of guests were wearing very stylish clothes.
• The number of employees needed is fifteen.
• A number of candidates were successful.
• The number of those who were successful is 37.
• A (surprising) number of candidates have applied.
• The number of unemployed people is causing alarm.
• A number of social problems are caused by unemployment.
• The number of people allowed into the museum is limited.
• A number of people were refused entry into the museum.
• There are a number of new recruits this year.
• Here is the number of those who were recruited this year.
• There are a number of different options to choose from.
• The number of options proposed is considerable.