“Can not” or “Cannot”?

We had a little debate internally on the correct spelling for “can not” in exception message strings.  One of the testers actually dug up a series of bugs where we changed one message back and forth several times.  Well, I am happy to say that we have the official word on this.  The UE manager for the .NET Framework weighted in with a definitive decree.  We have decided to use “cannot”. 


If this was a matter of needless debate on your team please feel free to put it to rest now and consider “cannot” the correct spelling.

Comments (20)

  1. Mitch Walker says:

    I know how you love Google as a reference. It quickly turns up these two hits:



    So it looks like the right choice was made. 🙂

  2. Don Newman says:

    Now that it is official I will no longer have to avoid that term in error messages.

  3. Rob says:

    "can not"

    (7 200 000 results)



    (57 300 000 results)

    The winner is: cannot

  4. We’ve not had Can Not vs Cannot on our team, but I’m glad you finally resolved the "matter" vs "mater" debate in this post 🙂

    Sorry, couldn’t resist, it IS a post about spelling after all 🙂

  5. Brad Abrams says:

    Ahh – thanks Larry… I should know better than to do a spelling relate post that late a night 😉


  6. Matt says:

    So what’s wrong with "can’t" ?

  7. John S. says:

    In a similar vein, hopefully someday we’ll all get "log in" right as two words. If it were one, the process of gaining access would be loginning after which you would be loginned.

  8. Jerry Pisk says:

    IIRC "log in" is correct when used as a verb, on a button or as a page title. But not as a label to the field where you’re entering your login [name]. And is it log in/out or log on/off? WinXP uses on/off…

  9. Matt, I think the answer is that it’s considered bad form to use contractions in error messages.

    But I’ve never really understood it.

  10. According to the Microsoft Manual of Style for Technical Publications 3.0 it is Log On and Log Off. Quote:

    log on to, log off from, logon (adj)

    Use log on to to refer to connecting to a network and log off from (or simply log off) to refer to disconnecting from a network. Do not use log in, login, log onto, log off of, logout, sign off, or sign on. An exception is when other terms are dictated by the interface.

    Use logon only as an adjective, as in "logon password," not as a noun.


    You are prompted for your password while logging on.

    Reconnect when you log on to the network.

    Some networks support this logon feature.

    Remember to log off from the network.


    You are prompted for your password during logon.

    Log in before you start Windows.

    Remember to log off of the network.

  11. Eric Newton says:

    Now thats interesting, posting google results as the deciding factor…

    Cannot is a valid word, according to the English dictionary:


    So I cannot see why its a big issue. I mean come on guys, cannot we all just get along?

  12. Eric Newton says:

    Microsoft Manual? Log on log off? I cannot see why any of that is important. Cannot or can’t? I’m so confused.

  13. Jerry Pisk says:

    Oh and does anybody actually use "can not"? I don’t think I’ve ever seen it split…

  14. Mike Scott says:

    What about "oriented", as in "object oriented?" This implies that the root verb is "to orient," when it’s actually "to orientate." The term should be "object orientated." If you believe that the root is "orient", then the noun should be "oriention," which I’ve never heard anyone use. If you’re going to use the term "object orientation", then the adjective is obviously "object orientated."

  15. What makes you think it’s to orientate? That means to turn to the East, as in the Orient. To orient oneself (small ‘O’) is to familiarize, whereas to be oriented around something is to be centered around it. Object orientation means centered around objects and comes from to orient not to orientate.

  16. Mike Scott says:

    Christian: "orientate" and "orient" both derive from "Orient", which itself derives from the latin "orire" meaning "to rise", i.e. it means where the sun rises or the east. That’s not in debate. What is in debate is the correct spelling of the past tense "orientated" or "oriented." If you use the spelling "oriented" then it’s also logical that you should use the noun "oriention" rather than "orientation."

    While we’re at it, how about the verb "to differ" and its derivative forms which are often used inconsistently. For example, "different than …" is often used, where the correct grammar is "different from …" Again, a simply examination of the various uses shows that it should be to differ *from*. For example, would you say, "the .Net API differs than the Win32 API" or "the .Net API differs from the Win32 API?" I’m betting it’s the second, but do you say "the .Net API is different than the Win32 API" or "the .Net API is different from the Win32 API." Again, the second is correct but I often hear and read the first form, frequently on MSDN <g>.

  17. Brad: Thanks tons. This issue just came up with us. It was nice to see that there was an official decision on this.

  18. Marcia Ferreira says:

    > Oh and does anybody actually use "can not"?

    You would be surprised, Jerry.

    > So I cannot see why its a big issue.

    Another issue here: "Its" and "It’s" are NOT interchangeable and I see a lot of people using "its" instead of "it’s".

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