Correlative conjunctions are pairs of words that connect words, phrases, or clauses that are grammatically equal. They work together to create a specific grammatical structure and meaning.
In the case of "not only," it is always paired with "but also," and they work together to create a parallel structure, emphasizing both parts of the sentence:
Not only did she win the race, but also she set a new record.
Other examples of correlative conjunctions include:
* either...or
* neither...nor
* both...and
* whether...or
* not only...but also