Can someone please help me with these grammar issues I am having?? First issue is, what's the deal with cannot? Why don't "donnot" "willnot" etc exist? Why just cannot? also is it still proper to space them apart like: "I can not go"??? My next issue is does can't, don't etc. really equal do not and cannot?? Like, are they completely interchangeable? When my teacher asks me "Didn't you do your homework?" Does that mean "Did not you do your homework?"? Sounds weird. Doest that make sense?? Another example: "Why can't I play" = "Why can not I play?"?? I know it probably makes me sound dumb but can anyone help explain?