The following is coming from the perspective of a native German speaker.
As far as I understand English grammar, most constructions are strictly right-associative:
Why (is (this flower (not (on (the table))))), but on the floor?
Why (is (not (this flower (on (the table))))), but the other one?
It wasn't always this way. If you look at old English literature and poetry, the grammar shared a closer affinity with the German language, where the "not" is more flexibly positioned. (The "not" is left-associative in German, but not in the whole sentence.) In German, the important part of a sentence is always at the beginning, where the interrogative pronoun is placed.
For example, if the following question is asked:
Where must this stay?/ Where has this to stay?
Then one might answer:
Here / Not here … must this stay! / has this to stay!
This does sound OK, or at least not too odd in German, but I believe that this sounds really strange for native English speakers.
The position of the word "not" can be a bit flexible in newer English language, as in the above sentence, but modern English usage allows this flexibility less.
Please correct me, if I'm wrong. (Or if my English is wrong.)