Correlative conjunctions work only in pairs:
- Either go to bed early this evening or stop complaining about being tired in class.
Both words make up the correlative conjunction. Alone EITHER is an indefinite pronoun and OR is a coordinating conjunction.
- Neither contestant nor his sponsor was willing to attend the lecture.
Both words make up the correlative conjunction. Alone NEITHER is an adjective and NOR is a coordinating conjunction.
not only/but also
- The newspaper reported that not only the hurricane but also the ensuing floods caused millions of dollars worth of damage.
- Does anyone know whether the president or the vice president was responsible for providing the announcement to the press?
Remember that when either is used without or and neither is used without nor, it acts as an adjective or pronoun.
- Either movie seems to be a good choice. (adjective)
- Either seems like a good choice to me. (pronoun)
- Neither book was good. (adjective)
- Neither was good. (pronoun)