Quick answer: Amount is used with uncountable nouns — things that are measured rather than counted individually, like water, time, or money: a large amount of research. Number is used with countable nouns — things you can count one by one, like people, cars, or mistakes: a large number of studies. This rule mirrors the less/fewer distinction. For a fuller definition, see the Cambridge Dictionary entry for ‘amount’.
Comparison Table
| Word | Use With | Common Examples | Example Sentence |
|---|---|---|---|
| amount | uncountable nouns | amount of water, time, money | The amount of traffic was surprising. |
| number | countable nouns | number of people, cars, mistakes | The number of cars on the road was surprising. |
Using Amount
Use amount with uncountable nouns — things that cannot be counted individually and have no plural form. These are often substances, abstract concepts, or mass nouns.
The amount of traffic was surprising.
A large amount of research supports this conclusion.
We have a limited amount of time to finish the project.
There was a huge amount of data to process.
Common Uncountable Nouns That Take Amount
The following nouns are uncountable and always take amount, never number: water, money, time, information, research, evidence, traffic, work, energy, knowledge, food, music, advice. You cannot say “a number of information” or “a number of money”.
She has an impressive amount of knowledge on the subject.
The amount of evidence against him was overwhelming.
Using Number
Use number with countable nouns — things you can count individually and that have a plural form (one car, two cars; one student, two students).
The number of cars on the road was surprising.
A large number of studies have been conducted on this topic.
The number of complaints received was higher than expected.
The number of students who passed was impressive.
The/A Large Number Of — Verb Agreement
Note that “a number of” takes a plural verb, while “the number of” takes a singular verb.
A number of students are waiting outside. (plural verb)
The number of students is increasing. (singular verb)
Common Mistakes
✗ A large amount of people attended the event.
✓ A large number of people attended the event.
Note: “People” is countable, so use number.
✗ A large number of research has been published.
✓ A large amount of research has been published.
Note: “Research” is uncountable. Use “a large number of studies” if you want to refer to individual items.
✗ We need less employees and a smaller amount of departments.
✓ We need fewer employees and a smaller number of departments.
Note: The less/fewer and amount/number rules are parallel. If you can use fewer, use number; if you can use less, use amount.
Tips to Remember the Rule
- Can you count it? If yes, use number. (number of mistakes → one mistake, two mistakes)
- Can you measure it? If yes, use amount. (amount of water → a litre of water, not “one water”)
- Link amount with less, number with fewer. Same rule, different words.
- Try adding a plural -s. If the noun takes a plural, use number; if not, use amount.
Also confusing: Less vs Fewer, Much vs Many, Accept vs Receive. Browse all confusing word pairs →
Quick Check: Amount or Number?
Four questions — fill in the blank with the correct word.
1. “The ___ of complaints received was higher than expected.”
2. “We have a limited ___ of time.”
3. “The ___ of students who passed was impressive.”
4. “There was a huge ___ of data to process.”
Frequently Asked Questions
What is the difference between amount and number?
Amount is used with uncountable nouns — things that are measured rather than counted individually, such as water, time, or money. Number is used with countable nouns — things you can count one by one, such as people, cars, or mistakes.
Can I say “a large amount of people”?
No. “People” is countable, so you should say “a large number of people”. Using “amount” with countable nouns is a very common mistake. Reserve “amount” for uncountable nouns like water, time, and money.
Is “amount” or “number” correct with “information”?
Use “amount” with “information” because information is uncountable in English. For example: “The amount of information available online is overwhelming.” You cannot say “a number of information”.
How is the amount vs number rule similar to less vs fewer?
The rule is identical: less/amount are for uncountable nouns, while fewer/number are for countable nouns. “Less water” matches “amount of water”; “fewer cars” matches “number of cars”. If you can use fewer, you should use number; if you can use less, use amount.
Can “number” be used with uncountable nouns?
No. “Number” is only used with countable nouns. You cannot say “a number of traffic” or “a number of research”. Use “amount” for uncountable nouns: “an amount of traffic”, “an amount of research”.
What are some examples of uncountable nouns to use with “amount”?
Common uncountable nouns that go with “amount” include: water, time, money, research, evidence, traffic, information, work, knowledge, energy, and food. These are things measured in bulk rather than counted individually.
What are some examples of countable nouns to use with “number”?
Common countable nouns that go with “number” include: people, cars, students, mistakes, studies, complaints, emails, questions, and books. These are things you can count individually: one car, two cars, three cars.
Is it “a large amount” or “a large number” of studies?
Use “a large number of studies” because “studies” is countable (one study, two studies). However, you would say “a large amount of research” because research is uncountable.
How do amount and number appear in academic writing?
In academic writing, both words are common. “A large number of studies have shown…” (countable) and “The amount of evidence suggests…” (uncountable) are typical patterns. Mixing them up is a common error that affects clarity and academic register.
Are there any exceptions to the amount vs number rule?
In informal speech, “amount” is sometimes used with countable nouns (“a large amount of people”), but this is considered incorrect in formal and academic writing. For IELTS, TOEFL, and other exams, always follow the standard rule: amount for uncountable, number for countable.