Correlative conjunction is the grammarian’s fancy term for a pair of conjunctions that join two matching sentence parts, such as not only … but also and both … and. When these conjunctions appear in your writing, you want to ensure the sentence parts they join are structured the same way. For example:
Not only was I sick, but I was also tired.
He not only will call but will also send flowers.
Both she and I have completed the coursework.
The book is both long and complicated.
In the first example, both parts of the sentence have a subject-verb structure. Our second example has conjunctions that are joining two verb phrases: will call and will send flowers. If you’re going to use not only, be sure to follow it with but also (or but … as well or but … too).
In the third example, both … and are joining she and I, subject pronouns for the verb have completed. The last example has conjunctions that are joining two adjectives describing book: long and complicated. In these cases, you could choose to drop both:
She and I have completed the coursework.
The book is long and complicated.
But if you use both to join two parts, you’ll need to follow it with and:
Wrong: The book is both long or complicated.
Right: The book is both long and complicated.
Some other correlative conjunctions to watch for:
- Although … nevertheless
- Although … yet
- As … as
- Either … or
- If … then (then can often be dropped to streamline the sentence)
- Just as … so also
- Neither … nor
- Since … therefore
- When … then (then can sometimes be dropped to streamline)
- Whether … or
Being aware of word pairs like this can help you quickly and subtly improve your writing.