'Either' ... 'or', 'neither' ... 'nor', and 'not only' ... 'but also' are all correlative conjunctions. They connect two equal grammatical items.
If,
for example, a noun follows 'either', then a noun will also follow 'or'. Read these examples:
"In the fall, Phillip will either start classes at the community college as his mother wishes or join the Navy, his father’s hope."
"Neither the potted ivy on the counter nor the dirty dishes in the sink have enjoyed water on their surfaces for the past week."
"Professor Wilson not only requires a 3,000-word research essay but also assigns a 500-word reaction paper every single week."
When you use correlative conjunctions, be careful about verb agreement.
If you connect two subjects with a correlative conjunction, the second one must agree with the verb that follows.
"Every single evening either the horned owl or the squabbling cats wake Samantha with their racket."
"Every single evening either the squabbling cats or the horned owl wakes Samantha with its racket."
When you use correlative conjunctions, be careful about pronoun agreement.
If you connect two antecedents with a correlative conjunction, the second one must agree with the pronoun that follows.
"Neither Yolanda nor the cousins expressed their disappointment when blind Aunt Sophie set down the plate of burnt hamburgers."
"Neither the cousins nor Yolanda expressed her disappointment when blind Aunt Sophie set down the plate of burnt hamburgers."
When you use correlative conjunctions, be careful about parallel structure.
'Either' ... 'or', 'neither' ... 'nor', and 'not only' ... 'but also' require special attention when you are proofreading for parallelism. Be sure that you have equal grammatical units after both parts of the conjunction.
- You can have two main clauses like this:
"Not only did Michael grill a steak for Tiffany, but he also prepared a hotdog for Rocket, her dog."
- Or you can shorten the sentence with two prepositional phrases:
"Michael grilled meat not only for Tiffany but also for Rocket, her dog."
- Or you can have two nouns as this version does:
"Michael grilled meat for not only Tiffany but also Rocket, her dog."
