What's the difference between amount and number?

The confusion between amount and number is common but can be easily overcome. They are not interchangable - their use relates to countable and uncountable nouns.

Amount

Use amount is with uncountable nouns and abstract nouns:

amount of time

amount of snow

amount of noise

amount of love (abstract noun)

amount of pride (abstract noun)

Number

Use number with countable nouns (things that can be counted):

number of cars

number of chairs

number of houses

number of topics

Number of people

Although it is grammatically correct to say a number of people, in casual English it is common to hear the amount of people. The amount of people is frequently used but not actually right. Be aware of this especially in formal situations or English language tests.

Now decide if these sentences need amount or number:

• 1) A large ___ of animals were sold.
  
  amount
  number
  
  
• 2) I wasn't expecting this ___ of work.
  
  amount
  number
  
  
• 3) The airline experienced an increased ___ of passengers in summer.
  
  amount
  number
  
  
• 4) I saw ___ of friends on my way to work today.
  
  a number
  an amount
  
  
• 5) Music gives me a huge ___ of pleasure.
  
  amount
  number
  
  
• 6) The company is trying to reduce the ___ of complaints it receives.
  
  number
  amount
  
  
• 7) The university has doubled its ___ of female engineering students.
  
  number
  amount
  
  
• 8) He's always had a large ___ of trust in me.
  
  amount
  number
  
  
• 9) What does the ___ of happiness we have depend on?
  
  number
  amount
  
  
• 10) The ___ of stress we have is hard to measure.
  
  amount
  number