Of all the types of conjunctions, Correlative Conjunctions are perhaps the easiest to identify as they always come in pairs, they always come together and they link two separate but related items of equal value.
Pretty much like socks do.
Common Correlative Conjunctions
These are the most common; as you can see the different options they joined ideas are equal in validity and importance.
I can either pick you up outside school or I can wait for you at the bus stop.
You can either take the train or the bus.
I’m the only graduate in the family. Neither my sister nor my brother finished university.
I neither smoke nor drink. But I do enjoy the occasional game of poker.
not only…but also
Not only was I able to get a discount on the table, but they also delivered it for free.
Not only are you a gentleman, but you are also a scholar.
Technically speaking, correlative conjunctions consist simply of a coordinating conjunction linked to an adjective or an adverb.
For example: either is an indefinite pronoun and or is a coordinating conjunction. Together they form a correlative conjunction.
Likewise neither is an adjective and nor is a coordinating conjunction. Together they form a correlative conjunction.
Conjunctions In English Grammar – a look at different kinds of conjunctions in English