The two midgets: ‘Is’ and ‘Not’. Two words unparalleled in their ability to create mischief. I’ll get to the first later; for now, the ‘Not.

Not; Null; Nothing; Nonsense; Never; Neither; Neutral, Naught. They all come from the same gene, the Sanskrit ‘Ña’.
One big troublesome joint-family.
The term ‘The-Not’ [‘Nought’] is the most terse of lingual Self-Eating Expressions going back directly to the lay-out of Yājñavalkya’s Rule. I use the better-known term ‘True-Nothing’ but as used they are perfectly synonymous. [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 to gether 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.
Note the self-referential trail.