Can Not or Cannot Quiz: Test Yourself
Five quick questions on can not or cannot. Pick an answer to get instant feedback.
Flip Cards: Quick Review
Hover over a card, or tap it on mobile, to see the meaning.
The standard one-word negative of “can.”
“I cannot open this file.”
Two words when “not” belongs to another phrase.
“You can not only sing but also dance.”
The informal contraction of “cannot.”
“I can’t find my keys.”
Two words to stress a choice or contrast.
“You can go, or you can not go.”
Writers often stop to ask can not or cannot because both look natural on the page. The good news is that the rule is simple: one form is the default, and the other has a few special jobs. This guide explains the difference between can not and cannot, shows when each is correct, and gives you quick tricks to choose with confidence.
| Term | Meaning | Part of speech / Category | Example sentence |
|---|---|---|---|
| cannot | Is unable to, or is not allowed to | Modal verb (negative) | Guests cannot enter after 10 p.m. |
| can not (+ “not only”) | “Can” followed by a separate “not” that belongs to another phrase | Modal verb + adverb | You can not only apply online but also by post. |
| can not (choice) | Stresses the negative option or a contrast | Modal verb + adverb | You can join the call or you can not; it’s up to you. |
| can’t | Informal contraction of cannot | Contraction | I can’t hear you. |
What does “cannot” mean?
Cannot means that someone is unable to do something or is not allowed to do it. It is the standard negative form of the verb “can,” and it is written as a single word.
You will see it in rules, instructions, emails and formal writing:
- Employees cannot share their passwords.
- I cannot open this attachment.
- The museum cannot accept large bags.
If you are unsure which form to write, “cannot” is the safe choice, and it suits formal writing best.
What does “can not” mean?
Can not is simply “can” followed by the separate word “not.” It is correct when “not” is part of a different phrase or when you deliberately set two options side by side.
The most common case is “not only… but also”:
- You can not only stream the show but also download it.
- She can not only sing but also play three instruments.
Here, “not” goes with “only,” so writing “cannot only” would be wrong. The second case is emphasis or choice: “You can accept the offer, or you can not.” Reading this aloud, you would pause between the two words.
Is “can not” wrong?
No, “can not” is not wrong, but it is less common and usually reserved for special situations. Most style guides prefer “cannot” unless the two words have separate jobs.
Many people write “can not” by accident when they mean “cannot,” especially in formal notices, policies and emails. That is why so many people search for the difference between can not and cannot. Choosing “cannot” avoids the problem.
Can not or cannot: which one should you use?
Use cannot unless “not” clearly belongs to another phrase or you want to stress a choice. In most everyday sentences, that means “cannot.”
The difference can even change meaning:
- We cannot wait to see you! (We are very excited.)
- We can not wait. (We are able to choose not to wait.)
You may also see “can’t” in casual writing. It means the same as “cannot,” but it is informal, so save it for texts, chats and relaxed emails.
Common mistakes with can not and cannot
- ✗ You cannot only pay by card but also by cash.
✓ You can not only pay by card but also by cash. - ✗ The manager can not attend today’s meeting.
✓ The manager cannot attend today’s meeting. - ✗ I can’not find my keys.
✓ I can’t find my keys. - ✗ We can not wait to see you!
✓ We cannot wait to see you! - ✗ Applicants can not apply after the deadline.
✓ Applicants cannot apply after the deadline.
How can you remember which one to use?
Start with “cannot” and only split the words if you have a clear reason. Here are three memory tricks:
- The “not only” test: If “only… but also” follows, keep the words apart: “can not only.”
- The one-word default: When in doubt, write “cannot.” It is correct in nearly every formal sentence.
- The contraction test: If you could write “can’t” in a casual version of the sentence, write “cannot” in the formal one.
FAQ: Can Not or Cannot
Is it ‘can not’ or ‘cannot’?
‘Cannot’ is the standard spelling in most sentences. Use ‘can not’ only when ‘not’ belongs to another phrase, such as ‘not only’, or when you want to stress a choice or contrast.
Is ‘can not’ grammatically wrong?
No. It is not wrong, but it is far less common than ‘cannot’. Most style guides prefer ‘cannot’ unless the two words have separate jobs.
What is the difference between cannot and can’t?
‘Can’t’ is the informal contraction of ‘cannot’. Both mean the same thing, but ‘cannot’ suits formal writing.
Is ‘cannot’ one word or two?
It is one word. Written as two words, ‘can not’ is used only in special cases, such as ‘not only’ or when stressing a choice.
Is there a difference in meaning between ‘cannot wait’ and ‘can not wait’?
Yes. ‘We cannot wait’ means we are very eager. ‘We can not wait’ means we are able to choose not to wait.
Conclusion
When you’re stuck on can not or cannot, write “cannot” in almost every case, and split the words only for “not only” or a deliberate contrast. Keep “can’t” for casual writing. Share this with someone who mixes these up!