1. used before a singular count noun when you mention one person or thing for the f
used before a singular count noun when you mention one person or thing for the first time, or when the exact one does not matter
Asher found a wallet under the bus seat this morning.
a + singular noun for first mention
Zuri is looking for a cafe with good soup near campus.
We need a ladder before we can paint the kitchen ceiling.
Putri heard a strange noise behind the garden wall.
文法句型
a + singular count noun
用法筆記
Before a vowel sound, English normally uses an instead. This sense introduces a new singular countable noun rather than one already known to the listener.
常見錯誤
2. used before a singular noun to show what kind of person or thing someone is, inc
used before a singular noun to show what kind of person or thing someone is, including a job, role, nationality, or class
Elena is a dentist who works nights at the children's hospital.
a + job noun after be
That insect is a beetle, not a baby cockroach.
Christopher became a Canadian citizen after living in Toronto for years.
Diya wants to be a pilot when she finishes school.
文法句型
be + a + job noun
be + a + type noun
用法筆記
This sense labels identity or membership. It is common after be, become, and similar verbs when the noun names a person's role or a thing's class.
常見錯誤
3. used with a singular noun to mean any member of a group, so the statement applie
used with a singular noun to mean any member of a group, so the statement applies to every example of that kind
A seat near the door is useful on a crowded train.
a + singular noun for a general truth
A good map can save hikers hours in thick fog.
A child needs sleep to learn well at school.
A cracked pipe can flood a whole kitchen in minutes.
文法句型
A + singular noun + general truth
用法筆記
Often used in rules, advice, and general truths. The sentence talks about one example as a representative of the whole class.
4. used before some uncountable nouns when you mean one particular kind, feeling, o
used before some uncountable nouns when you mean one particular kind, feeling, or example of it rather than the idea in general
A deep silence filled the room after the judge read the decision.
a + adjective + uncountable noun
Sivan answered with a calm that settled the whole room.
We felt a sadness that stayed with us all evening.
The village has a peace you never feel beside the highway.
文法句型
a + adjective + uncountable noun
a + uncountable noun + clause
用法筆記
Usually the noun is limited by an adjective or a following clause. Without that narrowing, the bare uncountable noun often appears with no article instead.
5. used before certain action nouns to talk about one instance of doing something
used before certain action nouns to talk about one instance of doing something
Aoi took a quick look at the map before turning left.
take a look for one brief action
Vinicius gave the door a hard push with his shoulder.
Please send me a reply before Friday afternoon.
The baby let out a loud cry when the bath water cooled.
文法句型
take a look
give a push
let out a cry
用法筆記
Common in light-verb patterns such as take a look or give a push. The noun refers to one event, not a physical object.
常見錯誤
6. used before a noun for one serving, container, sheet, piece, or similar unit of
used before a noun for one serving, container, sheet, piece, or similar unit of something, especially food, drink, or everyday items
Pim ordered a coffee and a cheese roll before class.
a + food or drink order
Please hand me a sheet of paper from the blue tray.
The nurse gave Asher a bottle of water after the race.
We bought a loaf of bread at the market near home.
文法句型
a + unit noun + of + noun
用法筆記
The noun after a names the unit or serving, not the material itself. Compare a loaf of bread with bare bread when speaking about the food in general.
7. used before the first of two singular nouns when the two things are normally und
used before the first of two singular nouns when the two things are normally understood as one set or one combined object
The waiter laid a knife and fork beside each plate.
article before the first noun in a fixed pair
Zuri packed a shirt and tie for the evening reception.
Please bring a cup and saucer to the front desk.
Christopher grabbed a bucket and mop before the store opened.
文法句型
a + noun + and + noun
用法筆記
The article appears only before the first noun because the two nouns are treated as one practical set, such as a knife and fork or a cup and saucer.
8. used before some number words to mean one, and used after fractions to connect t
used before some number words to mean one, and used after fractions to connect the fraction with its unit of measurement
The hall can hold a hundred parents during the school concert.
a before a number word meaning one
We walked one and a half miles before the rain started.
The recipe needs a quarter cup of warm milk.
A thousand paper cranes hung above the hospital entrance.
文法句型
a hundred
a thousand
one and a half + noun
a quarter + unit
用法筆記
After fractions, a links the number and the unit, as in half a mile or a quarter cup. In older or fixed patterns, it can also mean simply one before a number word.
9. used with time, money, distance, and similar measures to mean for each unit in a
used with time, money, distance, and similar measures to mean for each unit in a rate, frequency, wage, or price expression
The buses now come six times a day during the summer.
a meaning for each time period
Fresh cherries were selling for twelve dollars a kilo at noon.
Elena earns nine hundred dollars a week at the clinic.
The fountain fills the tank at twenty liters a minute.
文法句型
times a day
dollars a week
miles a minute
dollars a kilo
用法筆記
This sense turns the following noun into a measure for each unit. It is common with time, speed, wages, and prices.
常見錯誤
10. used before a personal name, family name, or named day or month to mean one exam
used before a personal name, family name, or named day or month to mean one example of it, often one not already identified
A Mr Lin called while you were out at lunch.
a before a name for an unidentified person
She married a Gupta from Jaipur and moved there soon after.
We visited on a Sunday in April when the streets were empty.
The meeting happened on a Monday, so half the staff were away.
文法句型
a + title + surname
a + family name
a + day or month
用法筆記
With names, it often means someone the speaker does not know personally. With days or months, it points to one instance rather than the day or month in general.