(3) CAUSAL, introducing a reason or cause. The chief ones are, for, therefore, hence, then.
(4) ALTERNATIVE, expressing a choice, usually between two things. They are or, either, else, nor, neither, whether.
Correlatives.
298. Some of these go in pairs, answering to each other in the same sentence; as, both...and; not only...but (or but also); either...or; whether...or; neither...nor; whether...or whether.
Some go in threes; as, not only...but... and; either...or...or; neither...nor... nor.
Further examples of the use of coördinate conjunctions:—
Copulative.
Your letter, likewise, had its weight; the bread was spent, the butter too; the window being open, as well as the room door.
Adversative.
The assertion, however, serves but to show their ignorance. "Can this be so?" said Goodman Brown. "Howbeit, I have nothing to do with the governor and council."