⚡ Quick summary
Cannot and can not mean exactly the same thing, but cannot is much more commonly used and has become the standard form in formal writing. In casual use, cannot and can not can be used interchangeably.
Cannot and can not are nearly identical except for that one space. Read on to understand the difference.
cannot vs. can not
The terms cannot and can not are identical in meaning and are typically considered to be alternate forms of one another. However, the form cannot is much more commonly used than can not. Cannot has become the standard form in formal writing (and is typically the form recommended by most grammar resources and style guides). In general, though, cannot and can not are interchangeable in both meaning and usage.
Although many other verbs can be paired with the word not to create a negative form, cannot is the only commonly used one that joins them together without a space.
Both cannot and can not are shortened as can’t. As is the case with all other contractions, can’t is very common in informal speech and writing.
