Correlative conjunctions

Correlative conjunctions are pairs of conjunctions that work together to coordinate two items. Correlative conjunctions work together in pairs, and there are some kinds of correlative conjunctions. They are :
either . . . or,
neither . . . nor,
not only . . . but also,  and whether…or.
They also establish certain relationship:

a. Condition: either . . . or and whether…or
    For example:
    1) Either you should study harder, or you should take a different course.
    2) I don’t know whether she would come or not.
b. Contrast: neither . . . nor
    For example:
    This job requires ability possessed neither by Jack nor by John.
c. Additional: not only . . . but also
    For example:
    The explosion destroyed not only the school but also the neighboring pub