Can Not vs Cannot
Published January 18, 2023. Updated January 18, 2023.
Can Not and Cannot. What’s going on there? Can is a helping verb, so adding not makes it negative. This happens with other helping verbs: do à do not; have à have not; could à could not. Do you notice that with all the negatives, the helping verb and the negative are two separate words? You would think that it works the same with can: can not. But it doesn’t. To make can negative, add the not and make it one word: Cannot. You might sometimes see can and not separate, but they will usually be followed by the word “only”: can not only. In this case, the negative not goes with “only,” which is why is it separated from can. Yeah, this is a little confusing…
Here are some definitions and examples to help make the use of these words clearer.
Can Not (Modal + Negative)
Can with negative “not,” usually followed by “only.”
Examples:
Ernie can not only speak English and German fluently, but he is also learning Italian.
The Judge’s decision can not only affect the defendant’s life but also the life of his entire family.
In both of these example sentences, it appears that can not is being used as the negative of can. However, the word not actually belongs to the phrase “not only”: Not only this, but also that. In both sentences, you can substitute the word can for other helping verbs and the meaning won’t change much:
- Ernie does not only speak English and German, but he is also learning Italian.
- The Judge’s decision will not only affect the defendant but also his family.
Since can and not don’t really go together in these examples, they cannot be made into the contraction can’t:
(Note: * indicates the sentence is incorrect)
* Ernie can’t only speak English and German, but he is also learning Italian.
* The Judge’s decision can’t only affect the defendant but also his family.
The sentences don’t make sense with the contraction.
Cannot (modal verb)
A helping verb indicating lack of ability; the negative of Can.
Examples:
After Thanksgiving dinner, I cannot eat one more thing, or I’ll pop.
The popularity of a Tweet cannot be an indication of its truthfulness.
In both of these sentences, cannot is being used as the negative of can. Since can indicates possibility or ability, cannot means no possibility, or no ability. In these sentences, you can make the contraction can’t:
- After Thanksgiving dinner, I can’t eat one more thing, or I’ll pop.
- The popularity of a Tweet can’t be an indication of its truthfulness.
The main difference between the word cannot and the contraction can’t is the level of formality. Cannot is more formal.
Main Points
- Can Not is not the negative of can. It will likely be part of a larger phrase, usually “can not only.”
- For the phrase “can not only,” the word not goes with “only,” not with
- Do not make the contraction can’t in these sentences. It will not make sense.
- Cannot is the negative of You can make the contraction can’t.