er
er — noun
1. the room or department in a hospital where doctors and nurses treat people who n
the room or department in a hospital where doctors and nurses treat people who need urgent medical care, especially those with serious injuries or sudden illness
Nila's mother was rushed to the ER after she complained of chest pains.
article usage: the ER
The ER at County Hospital treated over two hundred patients during the heatwave.
capitalized as ER in writing
Soraya had to wait three hours in the ER before a doctor could examine her.
Dr. Aylin has been head of the ER at St. Luke's for six years.
Paramedics called ahead to warn the ER that a burn victim was on the way.
- emergency department
more formal and clinical, commonly used in official hospital names
- casualty
British English term for the same department, used especially in the UK and Commonwealth
- A&E
short for Accident & Emergency, the standard British term
文法句型
the ER
go to the ER
in the ER
用法筆記
Often capitalized as ER in writing. In British English, the same department is usually called A&E (Accident & Emergency). Frequently appears in fixed phrases such as 'go to the ER' and 'taken to the ER.'
常見錯誤
2. a Latin abbreviation meaning 'Elizabeth the Queen,' used on British coins, stamp
a Latin abbreviation meaning 'Elizabeth the Queen,' used on British coins, stamps, and official documents during the reign of Queen Elizabeth II
The silver coin from 1965 still displays the ER cypher clearly on its face.
found on British coins
Official letters from Buckingham Palace during her reign carried the ER mark.
used on official documents
Brooke found the ER emblem on a post box near her grandmother's house.
Collectors pay extra for stamps where the ER watermark is clearly visible.
- royal cypher
the general term for the monogram of a reigning monarch, not specific to Elizabeth II
- cipher
alternative spelling of cypher, used in heraldic and royal contexts
文法句型
the ER cypher
marked with ER
用法筆記
Always written in capital letters. Found on British coins minted between 1953 and 2022, as well as on post boxes, public buildings, government documents, and royal warrants from Queen Elizabeth II's reign. The male equivalent for a king is R (Regina is replaced by Rex).
常見錯誤
er — abbreviation
1. a number in baseball scorekeeping that counts the runs a pitcher is responsible
a number in baseball scorekeeping that counts the runs a pitcher is responsible for allowing through normal hitting, not counting runs that scored because of fielders' mistakes.
The pitcher gave up only one ER in six innings of work.
collocation: give up + [number] + ER + innings
Kenji checked the ER total in the scorebook after the game.
A run that scores because of a fielding mistake is not an ER.
The newspaper listed each pitcher's ER beside their strikeout count.
- earned run
full form of the abbreviation
- unearned run
a run that scores because of a fielder's error, not charged to the pitcher
用法筆記
Always written as uppercase 'ER' in baseball scorekeeping. Commonly seen in box scores alongside innings pitched (IP) and strikeouts (K).
常見錯誤
2. the department in a hospital that gives immediate medical care to people with se
the department in a hospital that gives immediate medical care to people with serious injuries or sudden illnesses.
The ambulance took the injured cyclist straight to the ER.
collocation: taken to the ER
Sofia's mother waited in the ER while the doctors treated her.
The ER was crowded with patients on a busy Saturday night.
Doctors in the ER treat serious injuries and sudden illnesses every day.
- emergency department
fuller, more formal term for the same hospital unit
- ED
shorter abbreviation used in medical writing
- A&E
British English equivalent
- outpatient clinic
a facility for non-urgent, scheduled medical visits
用法筆記
Often shortened to 'ER' (pronounced as individual letters) in both spoken and written American English. In British English, the equivalent is 'A&E' (accident and emergency).
常見錯誤
er — exclamation
1. a vocal hesitation that people use to fill a brief silence while thinking over w
a vocal hesitation that people use to fill a brief silence while thinking over what to say or how to continue speaking.
Wei tried to recall the actor's name — er, right on the tip of his tongue.
hesitation while searching memory
Er, I am not sure that address is correct — let me check again.
hesitation when expressing doubt
The librarian's list had — er — about thirty books on ancient Rome.
Anya asked whether I wanted tea or coffee, and I said, Er, either is fine.
Er, could you explain that part again? I did not follow the argument.
常見錯誤
er — interjection
1. written on a medicine label or prescription to show that a drug is made to relea
written on a medicine label or prescription to show that a drug is made to release its active ingredients slowly over many hours, so the patient takes it less often than a regular version.
Joon's doctor switched him to an er version of the allergy pill.
er + noun (medication form)
Some er tablets must be swallowed whole and never crushed.
safety warning with er medications
The pharmacy carries both regular and er forms of that pain reliever.
Maeve takes one er capsule in the morning, and the effect lasts all day.
Check the label for the er marking before cutting any pill in half.
- long-acting
broader term used for any medication that works over a long period; 'er' is a specific technical label
- slow-release
common synonym; 'slow-release' is more descriptive while 'er' is an official abbreviation on packaging
- sustained-release
another similar pharmaceutical label; 'sustained-release' can have a slightly different release profile
- immediate-release
a medicine that releases all of its active ingredient at once, opposite of extended-release
文法句型
er + noun (medication form)
用法筆記
Frequently written in capital letters (ER) on medicine packaging. Do not crush or chew an er tablet, because the whole dose would be released at once instead of gradually.
常見錯誤
er — symbol
1. the two-letter code used on the periodic table and in chemical formulas to repre
the two-letter code used on the periodic table and in chemical formulas to represent erbium, a soft silvery metal from the lanthanide group that is used in laser technology and some types of glass
The periodic table box for element 68 shows Er above the name erbium.
position above element name on the periodic table
Ife checked the lab report and spotted Er among the rare-earth elements.
The glass contained a small amount of Er, which gave it a faint pink colour.
Students in Mei's chemistry class memorised that Er stands for erbium.
The isotope Er-166 is often used in scientific laser experiments.
用法筆記
Appears only in scientific and technical writing, especially chemistry. The symbol is case-sensitive: a capital E followed by a lowercase r — writing ER (both capitals) would be incorrect in standard notation.
常見錯誤
er — noun suffix
1. used to form nouns from verbs, describing a person whose job or regular paid act
used to form nouns from verbs, describing a person whose job or regular paid activity is to do that thing. For example, a teacher teaches, a baker bakes, and a writer writes for a living.
The teacher collects the homework every Monday morning.
teacher = teach + -er (occupational)
Noor works as a baker and starts her shift at four in the morning.
A good writer reads a lot before putting words on paper.
The dancer stretched for twenty minutes before going on stage.
Luca wants to become a painter when he grows up.
文法句型
[verb] + -er
用法筆記
The base verb sometimes changes spelling: drop final -e (dance → dancer), double the final consonant (run → runner), or change -y to -i (carry → carrier).
2. used to form nouns from other nouns or adjectives, referring to a person or thin
used to form nouns from other nouns or adjectives, referring to a person or thing that belongs to a particular group, place, or time, or is linked to it in some way. For example, a newcomer has recently joined a group, and an old-timer has belonged to it for a long time.
Hui is a newcomer to our team, so we help her find her way around.
newcomer = new + -er
The old-timers at the cafe still tell stories about life before smartphones.
Valentina is a regular at the weekend market and knows every seller by name.
The party-goers filled the street with music and laughter until sunrise.
文法句型
[noun/adjective] + -er
用法筆記
This sense often overlaps with "native of" (sense 3) but is broader — it covers association with any group, activity, or concept, not just places.
3. used to form nouns from the names of cities, regions, or countries, referring to
used to form nouns from the names of cities, regions, or countries, referring to a person who comes from that place or lives there. For example, a Londoner is someone from London, and a New Yorker is someone from New York.
As a Londoner, Eric knows which streets are best to walk through.
Londoner = London + -er
Many New Yorkers walk to work instead of driving a car.
New Yorker = New York + -er
The Berliner I met at the conference gave me great tips for visiting the city.
The -er suffix works well for London and New York, but not for all cities.
- -ite
used with some places (Brooklynite, Vancouverite) where -er sounds unnatural
文法句型
[place name] + -er
用法筆記
This pattern is most productive for US and UK city names (New Yorker, Londoner, Bostonian uses -ian). Not every city name forms a natural -er word; use the established demonym instead.
常見錯誤
4. used to form nouns from numbers, adjectives, or other nouns, referring to a pers
used to form nouns from numbers, adjectives, or other nouns, referring to a person or thing that possesses a particular quality such as an age, size, or school grade. For example, a three-year-old is a child who has the age of three years, and a fifth-grader is a child who has reached the fifth year of school.
A two-year-old learns to say simple words and follow basic instructions.
two-year-old = two years + old + -er (age attribute)
The little three-year-old put on her shoes all by herself this morning.
A double-decker bus travels along the main road every ten minutes.
Minho is a fifth-grader who loves playing soccer after school.
文法句型
[number/adjective/noun] + -er
用法筆記
This sense is commonly used with numbers for age (four-year-old) and school grade (third-grader). The whole compound noun is often hyphenated.
5. used to form nouns from verbs or nouns, referring to a device or living thing th
used to form nouns from verbs or nouns, referring to a device or living thing that creates or gives out something as its main function. For example, a cooker is a device that makes heat for cooking, a smoker releases smoke, and a good layer is a hen that gives many eggs.
This rice cooker can also steam vegetables and make soup.
rice cooker = rice + cook + -er (device that cooks rice)
Yael bought a new fryer that makes french fries with very little oil.
The farmer keeps a few good layers that produce eggs every morning.
An old smoker in the backyard turns fresh fish into smoky treats.
- -or
used for devices too (generator, radiator), often from Latin roots
文法句型
[verb/noun] + -er
用法筆記
This sense is less common than the agent-noun sense (sense 6). Most words here refer to devices or tools, not people. For example, a "cooker" is a kitchen appliance, not a person — a person who cooks is called a "cook."
常見錯誤
6. used to form nouns from verbs, referring to a person or thing that does a partic
used to form nouns from verbs, referring to a person or thing that does a particular action — without specifying that it is a job. For example, a runner is someone who runs, a reader is someone who reads, and a listener is someone who listens.
The runner trains every day for the city marathon in December.
runner = run + -er (agent noun)
Kevin is a fast reader who finishes one book every single week.
A good listener lets others finish speaking before giving advice.
The shopper put vegetables and bread into her basket at the market.
Maeve is a strong swimmer who can cross the lake in twenty minutes.
文法句型
[verb] + -er
用法筆記
Distinguish from sense 1 (JOBS OR PROFESSIONS): sense 6 covers any action, whether or not it is paid work. A "runner" (sense 6) is someone who runs for exercise; a "runner" in a hotel (sense 1) delivers items as part of a job.
常見錯誤
7. used to form nouns that refer to a person or thing that is the suitable target o
used to form nouns that refer to a person or thing that is the suitable target or intended receiver of an action — for example, a 'keeper' is something worth keeping, and a 'broiler' is a chicken raised for broiling.
The vase Soraya found at the market turned out to be a real keeper.
noun formed with -er meaning 'thing worth keeping'
The farmer raised three dozen broilers and sold them before winter.
Grandma bought a large roaster and filled it with potatoes and carrots.
After testing five cake recipes, Vivek chose the chocolate one as a keeper.
文法句型
[verb stem] + -er
用法筆記
This sense of the -er suffix forms patient nouns (the receiver of the action), unlike the more common agentive -er which names the doer. For example, a 'broiler' is a chicken suitable for being broiled, not the appliance or person that broils.
常見錯誤
8. used to form nouns from a preceding number or measurement combined with a base n
used to form nouns from a preceding number or measurement combined with a base noun, referring to a person or thing that is classified by that quantity — for example, a 'four-wheeler' is a vehicle with four wheels, and a 'ten-pounder' is something (such as a fish or weight) that weighs ten pounds.
The driveway was too narrow for Daichi's big four-wheeler to turn around.
noun formed with -er after a number and noun
Each ten-pounder was packed in ice and shipped out the same night.
Allison's son is a first-grader now and enjoys the daily story time.
A three-wheeler gives young children more stability than a standard bicycle.
文法句型
[modifier] + [noun/adjective] + -er
用法筆記
This suffix always attaches to a preceding modifier — typically a number and a noun (four-wheeler), an ordinal and a noun (first-grader), or a number and a unit of measurement (ten-pounder). The modifier cannot be omitted.
er — suffix
1. a suffix attached to a verb that turns it into a noun naming a person or thing t
a suffix attached to a verb that turns it into a noun naming a person or thing that carries out that action — for example, adding it to 'teach' gives 'teacher', meaning someone who teaches, and adding it to 'cook' gives 'cooker', a kitchen tool for cooking food.
Reema is a new teacher at the primary school near the park.
verb 'teach' + -er → person who teaches
The new electric cooker heats food much faster than the gas oven.
verb 'cook' + -er → thing that cooks
Wei works as a bus driver for the city transport company.
Pedro is a cleaner at the hospital and starts work at six every morning.
Elena is a careful reader who always finishes a book in just three days.
文法句型
[verb] + -er → [noun meaning person or thing that does the verb]
用法筆記
There are two common spelling rules a learner should know: if the verb ends in a silent -e, drop the -e before adding -er (bake → baker; drive → driver); if the verb is one syllable and has a consonant-vowel-consonant pattern, double the final consonant before adding -er (run → runner; swim → swimmer). The suffix is not used with all verbs — some agent nouns use -or (act → actor; govern → governor) or -ant (assist → assistant). The only reliable way is to learn each derived word as you encounter it.
常見錯誤
2. a suffix attached to the name of a field of study that creates a noun naming a p
a suffix attached to the name of a field of study that creates a noun naming a person who knows a great deal about that subject or is studying it — for example, a philosopher is someone who studies or has deep knowledge of philosophy.
The young philosopher spent months reading old books about how to lead a good life.
philosophy → philosopher: a person who studies philosophy
Élise became an astronomer after looking at stars through a large telescope.
Femi is a geographer who draws maps of rivers and mountains for the government.
Defne visits a psychologist twice a month to talk about how she manages her worries.
文法句型
[subject name] + -er → [noun meaning person who studies or knows a lot about that subject]
用法筆記
Most subject names that take this suffix end in -y (philosophy, geography, psychology) which changes to -er (philosopher, geographer, psychologist). The suffix -ist is also very common for the same purpose (biology → biologist; chemistry → chemist; economics → economist). There is no single rule for when to use -er vs -ist — it depends on the specific subject.
常見錯誤
3. a suffix attached to the name of a city, town, or region that creates a noun nam
a suffix attached to the name of a city, town, or region that creates a noun naming a person who lives there or was born there — for example, a New Yorker is someone from New York City, and a Londoner is someone from London.
A true Londoner knows the underground train map better than any tourist guide.
London → Londoner: a person from London
Eitan has lived in Berlin for twelve years and now calls himself a Berliner.
The villagers walk to the market together at sunrise every Saturday.
Hoa's cousin is a New Yorker living in an apartment near Central Park.
文法句型
[place name] + -er → [noun meaning a person who lives in or comes from that place]
用法筆記
This suffix works with some city names but not all. People from Paris are Parisians, not Parisers; people from Tokyo are Tokyoites, not Tokyoyers. The suffix is very common with smaller places, especially villages (villager, Highlander, islander). For most major world cities, you need to learn the correct demonym by checking a dictionary.
常見錯誤
4. a suffix attached to a noun or adjective that creates a noun naming a person who
a suffix attached to a noun or adjective that creates a noun naming a person who is involved with or belongs to that thing, activity, or state — for example, a teenager is a person between thirteen and nineteen years old, and a pensioner is someone who receives a pension after retiring from work.
The teenager spent the whole afternoon playing a new video game with her friends.
teenage → teenager: a person of teenage age
Nellie works as a volunteer at the animal shelter every Saturday afternoon.
Christopher's grandfather is a pensioner who enjoys gardening at the weekend.
The footballer scored an important goal in the final minute of the match.
Every summer the islanders prepare the fishing boats for the start of the season.
文法句型
[noun] + -er → [noun meaning a person connected with that thing]
[adjective] + -er → [noun meaning a person who has that quality]
用法筆記
Unlike sense 1 (DOER OF ACTION), this sense attaches to a noun or adjective rather than a verb. The resulting noun describes a person's connection to a situation, place, or characteristic rather than an action they perform. For example, a footballer does not 'football' (there is no such verb) — they are simply connected with the sport of football.
常見錯誤
5. a suffix attached to a noun that creates a noun or adjective naming a person or
a suffix attached to a noun that creates a noun or adjective naming a person or thing that has a particular number of parts, a particular size, or a particular distinguishing feature — for example, a double-decker bus has two levels ('decks'), and a six-footer is a person who is six feet tall.
The red double-decker bus carried tourists through the busy streets of the city centre.
double deck + -er → thing with two decks
Yumi is a six-footer who often plays basketball for the local weekend team.
The old three-wheeler moved slowly along the dirt road towards the village market.
A four-door car is much more useful for a family with two young children.
The first-grader waved goodbye to her mother at the school gate every morning.
文法句型
[number] + [noun] + -er → [noun/adjective meaning having that number of that part]
[noun] + -er → [noun meaning thing with that feature]
用法筆記
The number + noun + -er pattern is very productive in informal British English for describing vehicles and containers (a two-seater sofa, a three-bedroom house → three-bedroomer, a five-door car). The noun before -er is usually plural (six feet → six-footer, three wheels → three-wheeler). In American English, the noun is more often used without the -er suffix (a three-wheeled vehicle rather than a three-wheeler).