The two most deceptively simple words in the English Language are the midgets: ‘Is’ and ‘Not’. Existence and Absence. [Sanskrit, from the roots: as and na.]
We shall get to the ‘Is’ later. For now, the ‘Not’.
Not; Nothing; Nonsense; Never; Neither; Neutral. They all come from the same gene. One big mischievous joint-family. [I know of no word that more annoys a trained Logician than the word ‘Not’.]
And here is how the mischief begins:
North America and South America together make up the Americas. But North America and Not-North America?
We are not quite sure what exactly is: ‘North America and Not-North America’.
‘Not quite sure?’ That’s right. Not quite sure.
And not quite sure what exactly: ‘Not quite sure’ means.
Nor the above sentence.