Explanation at your level:
When you are ill, you feel bad. Your body is not happy. You stay in bed. You need medicine. You do not go to school or work. You say, 'I feel ill today.' It is like being sick. Drink water and rest to feel better soon!
If you are ill, you have a health problem. Maybe you have a headache or a cold. It is common to say 'I am ill' when you need to see a doctor. In some countries, people say 'sick' instead, but 'ill' means the same thing. Always tell your teacher if you are feeling ill at school.
The adjective ill describes a person who is suffering from an illness. It is often used in more formal contexts or in British English. You might hear phrases like 'severely ill' or 'mentally ill.' Remember that it is usually used after the verb 'to be.' For example, 'He has been ill for three days.' It is important to distinguish this from 'sick,' which can sometimes mean 'nauseous' in American English.
Using ill effectively requires understanding its register. While 'sick' is the default for most American speakers, 'ill' carries a slightly more clinical or serious tone. It is frequently used in collocations like 'terminally ill' or 'ill-advised.' When you describe a situation as 'ill-fated,' you are using the word in a more literary or sophisticated way to suggest bad luck or a negative outcome.
In advanced English, ill often appears in compound adjectives like 'ill-equipped,' 'ill-prepared,' or 'ill-tempered.' These constructions allow you to express that something is lacking or done poorly. The word carries a nuance of negativity that extends beyond physical health. In academic or formal writing, 'ill' is preferred over 'sick' to maintain a professional tone. Understanding these nuances helps you sound more precise and articulate in your communication.
At the C2 level, you appreciate the etymological depth of ill. It is not merely a synonym for 'unwell'; it carries historical weight related to 'badness' or 'evil.' You see it in idiomatic expressions that have survived for centuries, such as 'ill-gotten gains.' Furthermore, the distinction between 'ill' as a predicative adjective and its role as a prefix in compound adjectives demonstrates the flexibility of the word. Mastery involves knowing when to use it to convey a sense of misfortune or moral deficiency, rather than just physical sickness.
Word in 30 Seconds
- Means not healthy
- Used after verbs
- Common in UK
- Formal in US
The word ill is a classic way to describe someone who is not feeling healthy. Think of it as a broad umbrella term for when your body isn't working at 100% capacity.
While we often use it to talk about physical sickness, like having the flu or a stomach bug, it can also describe a general state of unwellness. It is a very common word in British English, whereas American English speakers often prefer the word 'sick' for everyday situations.
The word ill has deep roots in Old Norse, coming from the word illr, which meant 'bad' or 'evil.' It wasn't just about health back then; it could describe a person's character or even the weather!
Over centuries, the meaning narrowed down in English to focus primarily on health and physical discomfort. It is a great example of how words evolve from broad, moral concepts into specific, everyday descriptors for our physical state.
You will most often hear ill used as an adjective after a verb, such as 'He is ill' or 'She became ill.' It is slightly more formal than 'sick' in American English.
Common phrases include 'seriously ill' or 'critically ill' when discussing hospital situations. It is also used in the phrase 'ill health,' which acts as a noun phrase to describe a long-term condition.
1. Ill at ease: Feeling uncomfortable or nervous. Example: 'He felt ill at ease in the large crowd.'
2. An ill wind that blows nobody good: A situation that is bad for one person but good for another. Example: 'The storm destroyed my fence, but the local carpenter got a new job.'
3. Speak ill of someone: To say bad things about someone. Example: 'She never speaks ill of her colleagues.'
4. Ill-gotten gains: Money or items obtained dishonestly. Example: 'The thief could not enjoy his ill-gotten gains.'
5. Ill-fated: Destined to fail or have bad luck. Example: 'The expedition was ill-fated from the start.'
Ill is an adjective that is usually used predicatively (after the verb 'to be'). You would say 'He is ill,' but you wouldn't say 'He is an ill man'—that sounds quite formal or archaic!
The IPA pronunciation is /ɪl/. It rhymes with words like 'pill,' 'fill,' 'still,' 'hill,' and 'will.' It is a single-syllable word, making it short and punchy in conversation.
Fun Fact
It used to describe bad weather or bad character.
Pronunciation Guide
Short vowel sound.
Short vowel sound.
Common Errors
- Confusing with 'eel'
- Confusing with 'all'
- Adding extra syllables
Rhymes With
Difficulty Rating
Easy
Moderate
Easy
Easy
What to Learn Next
Prerequisites
Learn Next
Advanced
Grammar to Know
Adjective placement
He is ill.
Examples by Level
I feel ill.
I feel not-well.
Subject + verb + adjective.
He is ill.
He is sick.
Simple present.
Are you ill?
Are you sick?
Question form.
She is not ill.
She is healthy.
Negative form.
I was ill yesterday.
I was sick past.
Past tense.
Don't get ill.
Stay healthy.
Imperative.
The cat is ill.
The pet is sick.
Simple sentence.
Is he ill today?
Is he sick now?
Question.
She has been ill for two weeks.
I hope you don't get ill.
He looks a bit ill.
The teacher is ill today.
Many people are ill in winter.
Are you feeling ill?
I stayed home because I was ill.
He is recovering from being ill.
She is suffering from a long-term ill health.
He was taken ill during the meeting.
It is ill-advised to travel without insurance.
The patient is critically ill.
He felt ill at ease in the interview.
Don't speak ill of your neighbors.
The project was ill-fated from the start.
She is ill-prepared for the exam.
The company is ill-equipped to handle the crisis.
He was ill-tempered after the long flight.
The policy had ill effects on the community.
She is currently being treated for a serious ill.
It is an ill wind that blows nobody good.
His ill-gotten gains were confiscated.
The ill-conceived plan failed miserably.
She appeared ill at ease with the decision.
The candidate was ill-suited for the position.
The ill-defined goals led to confusion.
He was ill-disposed toward the new proposal.
The ill-fated voyage ended in disaster.
She was ill-served by her advisors.
The ill-natured comments were uncalled for.
Such ill-advised behavior is inexcusable.
The ill-starred lovers never met again.
The ill-omened raven sat upon the bust.
His ill-humored response silenced the room.
The ill-assorted group struggled to cooperate.
She was ill-acquainted with the local customs.
The ill-favored beggar sat by the gate.
The ill-starred venture cost him his fortune.
He was ill-versed in the intricacies of law.
The ill-bred youth lacked basic manners.
Common Collocations
Idioms & Expressions
"ill at ease"
uncomfortable or nervous
I felt ill at ease in the interview.
neutral"speak ill of"
say bad things about someone
Don't speak ill of the dead.
neutral"ill-gotten gains"
money earned dishonestly
He lost all his ill-gotten gains.
formal"an ill wind"
bad luck for one is good for another
It's an ill wind that blows nobody good.
proverbial"ill-fated"
destined to fail
The ill-fated project was cancelled.
neutral"ill-tempered"
easily angered
The ill-tempered dog barked at everyone.
neutralEasily Confused
Both mean unwell.
Sick is common in US.
I am sick vs I am ill.
Historical link.
Evil is moral; ill is physical.
An evil person vs an ill person.
Sentence Patterns
Subject + be + ill
He is ill.
Subject + become + ill
He became ill.
Subject + look + ill
You look ill.
Word Family
Nouns
Adjectives
Related
How to Use It
8
Formality Scale
Common Mistakes
Ill is an adjective, not a noun.
In US English, sick can mean vomiting.
Ill is rarely used before a noun.
Ill does not have an adverb form.
Use 'with' for the cause.
Tips
UK vs US
Use 'ill' in UK, 'sick' in US.
Placement
Put it after the verb.
History
It meant 'bad' long ago.
Rhyming
Rhyme it with 'pill'.
Memorize It
Mnemonic
I am ill, I need a pill.
Visual Association
A person in bed with a thermometer.
Word Web
Challenge
Use 'ill' in a sentence about a character in a book.
Word Origin
Old Norse
Original meaning: Bad or evil
Cultural Context
None, but can be sensitive when discussing terminal conditions.
UK uses 'ill' more; US uses 'sick' more.
Practice in Real Life
Real-World Contexts
Doctor's office
- I feel ill
- How long have you been ill?
- I am feeling quite ill.
Work
- I am calling in ill
- He is off ill
- Due to ill health
Conversation Starters
"Have you ever been seriously ill?"
"What do you do when you feel ill?"
"Do you prefer saying 'sick' or 'ill'?"
Journal Prompts
Write about a time you were ill.
Describe how you take care of yourself when ill.
Frequently Asked Questions
8 questionsYes, but ill is more formal.
It is rare and sounds formal.
No, we use 'badly' or other words.
Yes, but less than sick.
Illness.
Historically yes, but rarely now.
Like 'pill' without the 'p'.
Yes, 'The dog is ill'.
Test Yourself
I feel ___ today.
Ill describes health.
What does ill mean?
Ill means sick.
Ill is usually used before a noun.
It is used after the verb.
Word
Meaning
Matching synonyms.
Subject-verb-adjective.
Score: /5
Summary
Ill is a simple, effective word for being unwell.
- Means not healthy
- Used after verbs
- Common in UK
- Formal in US
UK vs US
Use 'ill' in UK, 'sick' in US.
Placement
Put it after the verb.
History
It meant 'bad' long ago.
Rhyming
Rhyme it with 'pill'.
Related Content
Related Phrases
More health words
ache
A2A continuous dull pain.
chemist
A2A person qualified to prepare and dispense medicinal drugs.
Consultation
B2A meeting with an expert or professional, such as a doctor or specialist, in order to seek advice or information.
doctor
A1A doctor is a person who has been trained in medicine and is qualified to treat people who are ill or injured. They examine patients, give advice on health problems, and prescribe medication when necessary.
exercise
A2Physical activity that you do to make your body strong and healthy. It can include activities like running, swimming, or going to the gym to improve your fitness.
fat
A2Having a large amount of excess flesh.
healthy
A2Healthy describes someone who is in good physical or mental condition and is not ill. It can also describe activities, food, or environments that help you stay well and strong.
hospital
A1A hospital is a large building where doctors and nurses provide medical care for people who are sick or injured. It contains specialized equipment and rooms for treatments, surgeries, and staying overnight while recovering.
hurt
A2To cause pain or injury to someone or yourself.
medicine
A2Medicine is a substance used to treat, prevent, or cure an illness or injury. It can also refer to the science and practice of diagnosing and treating patients to improve their health.
