Cannot or Can Not?

by Craig Shrives

Cannot or Can Not? (One Word or Two?)

Should I write "cannot" (i.e., as one word) or "can not" (i.e., as two)?
  • "Cannot" (one word) is the most common expansion of the contraction "can't." For example:
    • I cannot do it!
    • ("Can't" is usually expanded to "cannot.")
  • "Can not" (two words) is also an acceptable expansion of "can't," but it is less common and usually reserved for emphasis. For example:
    • I can not do it!
    • (This is considered more emphatic.)
cannot as one word or can not as two words?

More about "Cannot" and "Can Not"

"Cannot" and "can not" are interchangeable as expansions of the contraction "can't." However, the modern preference is to use "cannot." Of note, many spellcheckers even highlight "can not" as an error.

Example Sentences with "Cannot"

Here are some famous quotation featuring "cannot":
  • You cannot escape the responsibility of tomorrow by evading it today. (President Abraham Lincoln)
  • There cannot be a crisis next week. My schedule is already full. (Politician Henry A. Kissinger)
  • A flower cannot blossom without sunshine, and man cannot live without love. (Philologist Max Muller)
  • Three things cannot be long hidden: the sun, the moon, and the truth. (Buddha)

Example Sentences with "Can Not"

Remember that you can use "can not" to emphasize to the "not." Here are some examples:
  • Conflict can not survive without your participation. (Author Wayne Dyer)
  • I can not tolerate laziness!
  • (The two-word version makes it clearer that the word "not" should be emphasized. This is most useful in an exclamatory sentence, i.e., one that ends in an exclamation mark.)

Sometimes You Must Use "Can Not"

It is possible to see "can" and "not" as two separate words, especially with the correlative conjunction "not only...but also."
  • Danielle can not only cook but also bake.
  • My dog can not only roll over but also play dead.
  • I like that people who are not experts can not only understand but also become engaged by my work. (Critic Leslie Fiedler)
  • A very quiet and tasteful way to be famous is to have a famous relative. Then you can not only be nothing, you can do nothing too. (Political satirist P. J. O'Rourke)
In these examples, "cannot" as one word is not an option.
Put the Apostrophe in the Correct Place


If you're using the word "cannot," you can shorten it to "can't." Make sure you put the apostrophe in the correct place.

cannot can not
(This is an apostrophe error found in a Christmas cracker. If you make a mistake like this, people will laugh at you not with you.)
Interactive Exercise
Here are three randomly selected questions from a larger exercise, which can be edited, printed to create an exercise worksheet, or sent via email to friends or students.

See Also

adverse or averse? affect or effect? among or amongst? appraise or apprise? avenge or revenge? bare or bear? complement or compliment? dependant or dependent? discreet or discrete? disinterested or uninterested? e.g. or i.e.? envy or jealousy? imply or infer? its or it's? material or materiel? poisonous or venomous? practice or practise? principal or principle? cannot or can not? who's or whose? What are correlative conjunctions? What are contractions?