quantity
/ˈkwɒntəti/ (bre, ipa) · /ˈkwɑːntəti/ (ame, ipa) · /ˈkwän-tə-tē/ (ame, mw)
quantity — noun
- quantitysingular
- quantitiesplural
1. The total size or count of something that can be weighed, measured, or expressed
The total size or count of something that can be weighed, measured, or expressed as a number — for instance, the volume of water in a swimming pool or the number of seats in a theatre.
The recipe calls for a small quantity of salt, about half a teaspoon.
adjective + quantity of + uncountable noun
Jessica checks the quantity of milk left in the carton each morning before school.
quantity of + noun for checking amount
Large quantities of food and blankets reached the village after the flood.
The quantity of parking spaces at the shopping centre doubled after the expansion last year.
Hannah chose the bakery for its quality, not the quantity of cakes on display.
- amount
more common in everyday speech; used especially for uncountable things (amount of water, amount of time)
- volume
specifically for three-dimensional space or the amount of sound; more technical than quantity
- number
used only with countable items (number of people, number of chairs); not interchangeable with quantity for uncountable nouns
文法句型
quantity of + noun
quantities of + noun
adjective + quantity of + noun
用法筆記
Quantity is the most general word for 'how much' or 'how many'. It is often contrasted with quality, which describes how good something is rather than how much of it exists. In everyday speech, 'amount' is more common for uncountable nouns and 'number' for countable nouns; 'quantity' sounds slightly more formal.
常見錯誤
2. a large or more-than-enough amount of something — used when the size or number i
a large or more-than-enough amount of something — used when the size or number is important or impressive, such as a quantity of rice stored in a warehouse or a quantity of steel needed for a building project.
The warehouse contains a quantity of rice that feeds a whole region for a month.
a quantity of + noun (large amount in storage)
Arjun ordered a quantity of steel beams for the new bridge across the river.
ordered a quantity of + noun (construction context)
Quantities of old letters and photos were discovered in boxes under the stairs.
The sheer quantity of books in the library on ancient Egypt surprised even the professor.
文法句型
a quantity of + noun (singular/uncountable)
quantities of + noun
用法筆記
In this sense, 'a quantity of' often implies a notably large amount, but the exact size depends on context — a 'quantity of medicine' might be just a few bottles while a 'quantity of grain' could be many tonnes. The phrase 'in quantity' (without 'a' or 'of') means 'in large amounts' and comes before a verb or at the end of a clause.
常見錯誤
3. a value or amount that can be expressed as a number in a mathematical equation o
a value or amount that can be expressed as a number in a mathematical equation or scientific calculation — for example, the speed of light, the temperature of a liquid, or the variable x in an algebraic formula.
The students learned to solve for the unknown quantity x in the algebraic equation.
unknown quantity (math term for a variable)
In E = mc², each letter stands for a physical quantity like energy or mass.
physical quantity (science term)
The chemist measured the quantity of heat released during the reaction.
A vector quantity like velocity has both size and direction, unlike a simple number.
The lab report must state the exact quantity of each substance used in the experiment.
文法句型
a/the + adjective + quantity
physical/mathematical/unknown + quantity
用法筆記
In mathematics and science, 'quantity' refers specifically to a measurable property that can be assigned a number and a unit. Unlike sense 1, this sense is always technical and precise. Common compound terms include 'physical quantity', 'vector quantity', 'scalar quantity', and 'unknown quantity'.