で

Etymology 2
Originally a contraction of, later treated as a conjugation of the copula.

Particle

 * 1) at:
 * 2) with, by, using:
 * 3)  in:
 * 1)  in:
 * 1)  in:
 * 1)  in:

Adverb

 * : and then; therefore

Verb

 * 1) is/am/are ... and:

Etymology 3
Considered to be a contraction of, where the ni is the continuative form of the negative auxiliary. In use since Early Middle Japanese, and first attested in  of the late 800s.

Etymology 4
Corrupted from.

Particle

 * 1)  sentence-ending particle signifying emphasis