Cool MateCan't vs Unable
When to use each in English, with meaning, register, and examples.
Can't
Top 1,000 (very common)
Unable
Top 2,000 (common)B1adjective
Most common: Can't
| Can't | Unable | |
|---|---|---|
| Pronunciation | 🇬🇧 //kɑːnt//🇺🇸 //kænt// | 🇬🇧 /["/ʌnˈeɪbl/"]/🇺🇸 /["/ʌnˈeɪbl/"]/ |
| Meaning | Cannot; not able to do something. | not able to do something |
| Example | I can't attend the meeting tomorrow. | I was unable to attend the meeting due to a family emergency. |
| Register | Neutral | Neutral |
| How common | Top 1,000 (very common) | Top 2,000 (common) |
| CEFR level | - | B1 |
| Part of speech | adjective | |
| Collocations | can't help, can't wait, can't believe | appear, be, feel, completely, quite, totally, unwilling or unable |
| Antonyms | can, able | able, capable |
| Common mistakes | Confused with 'can' - remember 'can't' means unable., Omitting the apostrophe - always write 'can't', not 'cant'. | Confused with 'unable to' and 'not able to' — they mean the same but usage can vary., Using 'unable' without a following action verb., Misplacing adjectives — remember 'unable' always describes capability. |
| Usage notes | Use in informal spoken or written contexts. It's considered casual and may not be appropriate for formal writing. | Use 'unable' in situations where someone or something lacks the ability to perform an action. It's appropriate in both spoken and written contexts, but avoid in very casual conversations. |
Frequently asked questions: Can't vs Unable
What's the difference between Can't and Unable?
Can't: Cannot; not able to do something. Unable: not able to do something
Which is more common: Can't and Unable?
Can't is the most common in everyday English.
Can you show an example of each?
Can't: I can't attend the meeting tomorrow. Unable: I was unable to attend the meeting due to a family emergency.
Can I use Can't and Unable interchangeably?
Not always. Can't and Unable 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.