Cool MateIll vs Sick
When to use each in English, with meaning, register, and examples.
Ill
Top 2,000 (common)A2adjective
Sick
Top 1,000 (very common)A1adjective
Most common: Sick
| Ill | Sick | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/ɪl/"]/🇺🇸 /["/ɪl/"]/ | 🇬🇧 /["/sɪk/"]/🇺🇸 /["/sɪk/"]/ |
| Meaning | not well; feeling sick | Feeling unwell or ill. |
| Example | She felt ill after eating too much candy. | I feel sick after eating too much candy. |
| Register | Neutral | Neutral |
| How common | Top 2,000 (common) | Top 1,000 (very common) |
| CEFR level | A2 | A1 |
| Part of speech | adjective | adjective |
| Collocations | appear, be, feel, critically, dangerously, desperately, with, from | be, look, become, chronically, desperately, extremely, from, with, be off sick, be, feel, look, horribly, very, violently, with, be as sick as a dog, sick to your stomach, be, become, get, heartily, really, absolutely, of, sick and tired of something, sick to the back teeth of something, sick to death of something, be, seem, sound, extremely, fairly, very, sick in the head, be, seem, sound, extremely, fairly, very, sick in the head |
| Antonyms | healthy, well, fit | healthy, well |
| Common mistakes | Confused with 'ill' as in 'bad' versus 'sick'., Using 'ill' to describe emotional states without context., Incorrectly spelling 'ill' as 'il'. | Confused with 'sick' vs 'ill' — 'ill' is more formal., Using 'sick' to mean healthy — common in slang., Misplacing 'sick' in a sentence. |
| Usage notes | Used to describe someone who is not feeling well. Appropriate in both formal and informal contexts. Not used to describe emotional states unless specified (e.g., 'ill at ease'). | Used to express physical illness or emotional disgust. In slang contexts, it can describe something awesome. Avoid misuse in formal writing. |
Frequently asked questions: Ill vs Sick
What's the difference between Ill and Sick?
Ill: not well; feeling sick Sick: Feeling unwell or ill.
Which is more common: Ill and Sick?
Sick is the most common in everyday English.
Are Ill and Sick the same CEFR level?
Ill: A2, Sick: A1 on the CEFR scale.
Can I use Ill and Sick interchangeably?
Not always. Ill and Sick are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.