Not every bird can fly. = Every bird can't fly.吗?

Not every bird can fly. = Every bird can't fly.吗?
Not every bird can fly. = Every bird can't fly.吗?

Not every bird can fly. = Every bird can't fly.吗?
对的,均是部分否定.

≠

不可以，前面是部分否定，后面是全部否定了

不等于，
not every是不完全否定句式，意思是“不是每个..”
every .. not是完全否定句式，意思是“每个都不..”

Not every bird can fly :并不是每只鸟都会飞。
Every bird can't fly.: 每只鸟都不会飞。
两个句子不是同义句。含义表达不一致。