Cool MateImpossible vs It can't be vs Not possible
When to use each in English, with meaning, register, and examples.
Impossible
It can't be
Not possible
| Impossible | It can't be | Not possible | |
|---|---|---|---|
| Pronunciation | 🇬🇧 /["/ɪmˈpɒsəbl/"]/🇺🇸 /["/ɪmˈpɑːsəbl/"]/ | 🇬🇧 //ɪt kɑːnt biː//🇺🇸 //ɪt kænt bi// | 🇬🇧 //nɒt ˈpɒsəbl//🇺🇸 //nɑt ˈpɑsəbl// |
| Meaning | Not able to happen or be done. | It is not possible. | Something that cannot happen or be done. |
| Example | Climbing that mountain seems impossible without proper training. | When he said he could lift that car, I thought, 'It can't be!' | It is not possible to finish the project without more time. |
| Register | Neutral | Neutral | Neutral |
| How common | Top 1,000 (very common) | Top 2,000 (common) | Top 2,000 (common) |
| CEFR level | A2 | - | - |
| Collocations | appear, be, look, absolutely, completely, downright, for, be, become, find somebody, really, absolutely, completely | it can't be true, it can't be real, it can't be happening, it can't be serious | not possible to achieve, not possible due to circumstances, not possible at this time, not possible without effort |
| Antonyms | possible, feasible, achievable | - | - |
| Common mistakes | 'Impossible' is sometimes confused with 'unbelievable' but they are not the same., Learners might use 'impossible' to describe very challenging tasks instead of things that cannot be done at all., 'Impossible' is often incorrectly combined with less strong modifiers, like 'very impossible'. | Omitting 'it' and saying just 'can't be'., Using 'can't' in very formal speech., Confusing with 'it shouldn’t be' which implies advice rather than disbelief. | Confusing with 'impossible' as it is less formal., Using 'not possible' when something could be possible with effort., Misplacing the phrase in a sentence leading to awkward construction. |
| Usage notes | Use 'impossible' to describe something that cannot be achieved. It’s suitable for both spoken and written English but may be too strong in polite contexts. | Used to express disbelief or rejection of a statement. Appropriate in both spoken and written contexts. Avoid in overly formal settings. | Use 'not possible' in everyday contexts to indicate something is impractical or unachievable. Avoid overusing in formal writing. |
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Frequently asked questions: Impossible vs It can't be vs Not possible
What's the difference between Impossible, It can't be, and Not possible?
Impossible: Not able to happen or be done. It can't be: It is not possible. Not possible: Something that cannot happen or be done.
Which is more common: Impossible, It can't be, and Not possible?
Impossible is the most common in everyday English.
Can you show an example of each?
Impossible: Climbing that mountain seems impossible without proper training. It can't be: When he said he could lift that car, I thought, 'It can't be!' Not possible: It is not possible to finish the project without more time.
Can I use Impossible, It can't be, and Not possible interchangeably?
Not always. Impossible, It can't be, and Not possible 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.