Cannot vs can not?

Cannot” is the formal form of “can’t” and “can not.” English speakers can use “cannot” and “can not” interchangeably, but “cannot” is more common and accepted amongst English audiences.

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What is the difference between cannot and can not?

If someone is unable to do something, do you write “cannot” or “can not”? As it turns, you can use both! However, the word “cannot” is more common for English speakers because it’s the standard English form of “can’t” or “can not,” (but only when all three expressions share the same meaning). 

Indeed, the phrase “can not” can function as two separate words, and most reputable sources don’t make their distinctions easy to understand. So if you’re feeling stuck between which word to use, The Word Counter is here to bring more clarity to your writing questions. 

Quick writing tips for cannot vs. can not:

  • The definition of “cannot” is ‘can not.’
  • Cannot” is the negative form of “can.” 
  • Can’t” is an informal contraction of ‘cannot.’ 
  • The phrase “can not” contains the positive form of “cannot,” so the two expressions can have different meanings. 
  • For the sake of clarity, avoid using “can not” if the intended meaning is “cannot.” 

What is the definition of cannot?

The word “cannot is an auxiliary verb that English speakers use for questions, answers, and statements. The literal definition of “cannot” is ‘can not’ or ‘to be incapable’ because it’s the opposite of “can” (i.e., ‘to be able’). 

For example, 

“I cannot wait any longer.” 
“The children cannot read yet.”
“We cannot tell the difference between the twins.” 

Can’t” is a contraction or short form of “cannot,” which uses an apostrophe to join “can not” into the one-word form. For this reason, it’s grammatically acceptable to use “cannot,” “can’t,” and “can not” for the definition of “cannot.” 

What does “can not” mean?

There are times when “cannot” and “can not” have different meanings. Because the verb “can” means ‘to be able,’ English speakers use it within “can not” phrases to explain an option or make a statement. For example, 

“I can sing, or I can not sing.” 
“I can not only sing, but I can dance too.”

The phrasal form of “can not” is confusing for native speakers and ESL students alike because “cannot” is also found within expressions like “cannot but” or “cannot help but.” For example, 

“After hearing the news, I cannot but cry.”
“She cannot help but enjoy the sunshine.”

In this sense, the correct word to use is “cannot” because the intended meaning of the phrase conveys “to have no choice except to do something.” 

How to use cannot vs. can not in a sentence?

Learning how to use “cannot” and “can not” correctly is difficult for many reasons. Anytime we read the news, we’re bound to find both forms for the definition of “cannot.” But this doesn’t mean the two expressions always share the same meaning. 

When do “cannot” and “can not” mean the same thing?

Cannot” and “can not” share the same meaning when discussing an action that isn’t possible. For example,


“If your child cannot run or jump from standing, let your doctor know.” –– The New York Times
“If the spelling and grammar checker in Microsoft Word cannot recognize the misuse of affect and effect, then how can it be trusted …” –– Hartford Courant


“Officials said the government can not cover its bills and faces a $46 million deficit.” –– NPR
“It can not be identified by Facebook as the malware displays in front of the legit app ….” –– Sunderland Echo

When do “cannot” and “can not” have different meanings?

If “can not” forms part of another construction like “can not only but …,” the phrase has an entirely different meaning. In this case, the word “can” is a helping verb that allows “can not only but …” to mean “but also …

For example, 

“Studies show that eating the proper amount of protein can not only build muscle but accelerate fat loss.” –– The New York Times
“If we do the same, we can not only keep our hospitals from overloading but also buy researchers time …” –– The Washington Post

Which is correct: cannot or can not?

Whether you use American English or British English, “cannot” is the best form to use when “can’t” and “can not” share the same definition. Replacing “cannot” with “can not” is just unnecessary, but it’s very uncommon outside of the United States. 

The second best form is “can not,” unless you’re using it for phrases like “can not only” (then, it’s the best form for the context). The contractioncan’t” is only appropriate for informal writing.

Which came first: cannot or can not?

The Oxford English Dictionary (OED) defines “cannot” as “the ordinary modern way of writing can not,” which infers that the two-word form entered the English Language before “cannot” or “can’t.” Admittedly, there is little known about the histories of “cannot” and “can not,” but we can back-track their etymologies through the verb “can.” 

The modern use of “can” means ‘to be able’ or ‘to know through collective knowledge,’ a definition stemming back to Old English cunnan. According to The Oxford Dictionary of Word Histories, Old English cunnan is an Indo-European root that meant ‘to know’ and later ‘know how to do’ (Chantrell 80). 

Putting two-and-two together, we can suggest that if cunnan means ‘to know,’ then the original meaning of ne cunnan is ‘to not know.’ How “can not” morphed into the standard “cannot” is a mystery, but according to the Online Etymology Dictionary, the contraction of “can’t” didn’t enter the English lexicon until 1706

How to remember the difference between cannot and can not?

If you’re struggling to decide whether “cannot” or “can not” is more appropriate for a sentence, try replacing “can not” with “can’t.” If the sentence no longer makes sense, use “can not.” But if the sentence retains its original meaning, use the formal “cannot.” 

Example 1:

“We can not afford to visit Universal Studios” or “We can’t afford to visit Universal Studios”?

Answer = both are correct, use “cannot.”

Example 2:

“I cannot help but love her” or “I can’t help but love her”?

Answer = both are correct, use “cannot.”

Example 3:

“The software can not only correct typos, but it provides word suggestions” or 
“The software can’t only correct typos, but it provides word suggestions”?

Answer = the sentence with “can’t” does not make sense, use “can not.” 

Test Yourself!

Test how well you understand the difference between cannot vs. can not with the following multiple-choice questions. 

  1. True or false: Cannot, can not, and can’t are all acceptable spellings for formal writing such as AP style or MLA. 
    a. True
    b. False
  2. For phrases like “can not only but,” the words “can not” represent __________. 
    a. Two separate words
    b. A single word
    c. Part of a set phrase
    d. A and C
  3. What’s the difference between cannot and can’t?
    a. Formality
    b. An apostrophe 
    c. One word is a contraction
    d. All of the above
  4. English speakers are more likely to use ___________ instead of ___________. 
    a. Cannot
    b. Can’t
    c. Can not
    d. Answer
  5. “Can not” is to “can’t,” as __________ is to ______________. 
    a. Couldnot, couldn’t
    b. Willnot, won’t
    c. Would not, wouldn’t
    d. A and B


  1. B
  2. D
  3. D
  4. A
  5. C

Photo sources

  1. Photo by Andrijana Bozic
  2. Photo by Glenn Carstens-Peters 


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  2. Cannot.” MacMillan Dictionary, Macmillan Education Limited, 2020.
  3. Cannot.” The Dictionary, Merriam-Webster Inc., 2020.
  4. Cannot (help) but.” MacMillan Dictionary, Macmillan Education Limited, 2020.
  5. Can’t.” Lexico, Oxford University Press, 2020.
  6. Chantrell, Glynnis, ed. “Can [1].” The Oxford Dictionary of World Histories, Oxford University Press, pp. 80.
  7. Conan, Neal. “What Happens When A City Declares Bankruptcy.” Talk of the Nation, NPR, 11 July 2012. 
  8. Harper, Douglas. “Cannot (v.).” Online Etymology Dictionary, 2020. 
  9. McArdle, Megan. “When a danger is growing exponentially, everything looks fine until it doesn’t.” The Washington Post, 10 Mar 2020. 
  10. McFadden, Mark. “Programs that check grammar and spelling are letting students down. Here’s why.” Hartford Courant, 1 Mar 2020. 
  11. MacLean Weir, Meghan. “Your 4-Year-Old.” The New York Times, 18 Apr 2020. 
  12. O’Connor, Anahad. “How to Get Strong.” The New York Times, n.d.
  13. Rendall, Stephanie. “Android scam warning: 25 malicious Google Play apps to delete from your device due to personal data threats.” Sunderland Echo, 2 July 2020. 
  14. Usage and Grammar.” The Chicago Manual of Style, 17th ed., The Chicago Manual of Style Online, 2020.