Not Only / But Also: When and How to Use

First of all, to understand these four words, let’s discuss how they operate together grammatically. “Not only…but also” is known as a correlative conjunction. YourDictionary.com defines correlative conjunctions as tag-team conjunctions, explaining, “They come in pairs, and you have to use both of them in different places in a sentence to make them work.” 

Here are a few other pairs of conjunctions:

  • either…or
  • both…and
  • whether…or
  • neither…nor
  • not…but
  • as…as
  • such…that
  • scarcely…when
  • as many…as
  • no sooner…than
  • rather…than

 

All correlative conjunctions connect and compare two distinct ideas, descriptions, or actions. Each pair must be used in the order listed above. 

So, with “both…and,” the word order cannot be switched to “and…both.” 

Incorrect: She is and lovely both strong.

Correct: She is both lovely and strong.

Now, let’s look at an example sentence using “not only…but also.”

The day was not only long but also rainy. 

In this sentence, “not only…but also” works to emphasize the first description by intensifying the meaning with a secondary description. Generally, that’s how “not only…but also” functions—it adds emphasis and intensity to the first idea, description, or action.

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What Parts of Speech Should Follow?

Auxiliary Verbs

Especially when “not only” appears at the beginning of a sentence, you can expect to see a helping verb (also known as an auxiliary verb) next.

Not only was she a good listener, but she was also a great cook. 

The example above shows that “but also” does not have to be placed side-by-side. In this case, “she was” breaks up the two words. Still, “but also” must appear in the second half of the sentence and in the correct sequence. 

Not only did we arrive late but also at separate times. 

Here, you can see that the normal rules for comma usage apply. As with a coordinating conjunction, when “but” is followed by an independent clause, you use a comma. Otherwise, you don’t need one. 

Adjectives

You can follow “not only…but also” with adjectives or descriptive phrases. Just be sure to use parallel structure, so that you’re comparing an adjective with another adjective or a descriptive phrase with a similar descriptive phrase. 

She was not only wise but also kind. 
The title seemed not only confusing to read but also difficult to say. 

In both of these examples, the subject and verb appear before the correlative conjunction in the first part of the sentence. Since dependent clauses follow the word “but” in both sentences, commas are not needed. In the second example above, notice that the descriptive phrases have parallel structures. They’re both using an adjective + prepositional phrase, which ensures that the comparison is as neat as possible. While it’s not incorrect to eschew parallelism, writing “not only…but also” sentences with parallel structure makes them easier to read and understand. 

Nouns

You can compare nouns or noun phrases with “not only…but also.” 

She invited not only Tim but also John.

In the beginning of the sentence, the subject and verb both precede the first part of the correlative conjunction. Next, two proper nouns are emphasized and intensified. It would be equally correct to write, “She invited Tim and John.” The “not only…but also” construction serves to emphasize the fact that both people received invitations rather than just one of them. 

He considered not only the house on the hill but also the apartment near the shore. 

The second sentence employs the same basic construction, but it compares noun phrases rather than proper nouns. 

Verbs

In all “not only…but also” sentences, you compare two pieces of information. Often, the comparison is between verbs or verb phrases. For instance, let’s take one of the examples above and rewrite the sentence so that the relationship between two actions becomes the focus. 

He not only considered the house on the hill, but he also contemplated the apartment near the shore.

Notice that the main verbs have parallel structure—considered and contemplated. Again, using the same verb form for the first and second part of the sentence will allow your reader to follow your logic more easily. 

They not only run but also swim. 

Again, there’s no need to use a comma because the second clause is dependent. The two verbs have the same verb form, present simple tense, which maintains the parallel structure.

Variations on Not Only / But Also

Sometimes the phrase “not only” can be replaced by “not alone” or “not just.” Similarly, “also,” “but too,” and but as well” can be good substitutes for “but also.” 

Not only was he strong, but he was smart as well

  • not just…but also
  • not only…also
  • not only…but too
  • not only…but as well
  • not alone…but also

Sources:

  1. https://dictionary.cambridge.org/us/grammar/british-grammar/not-only-but-also
  2. https://grammar.collinsdictionary.com/us/easy-learning/auxiliary-verbs
  3. https://www.quickanddirtytips.com/education/grammar/not-only-but-also