When not only is followed by but also (or simply but), it’s considered good form to make sure the parts that follow each set of words are formatted the same way.
Examples of ‘Not Only But Also’
For example, this sentence is good because it uses two noun phrases:
Aardvark is not only a great fisherman but also a great friend.
A great fisherman is a noun phrase and it follows not only, and a great friend is a noun phrase and it follows but also.
Keep It Parallel
Sometimes people write sentences like this, in which the parts aren’t parallel, and that can be called out as bad style:
Aardvark is not only a great fisherman but also works hard to be a good friend.
A great fisherman follows not only and is a noun phrase, but works hard to be a good friend follows but also and is a verb phrase. Since one is a noun phrase and one is a verb phrase, they don’t match grammatically, and that’s why it’s bad.
If you want to use a verb phrase, you can rewrite the first part to match:
Aardvark not only excels at fishing but also works hard to be a good friend.
That’s your Quick and Dirty Tip, try to use parallel elements when you’re writing a sentence that uses not only with but also.
This article originally appeared January 29, 2011, and was updated January 27, 2017.