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Rule of Parallel Structure

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Though we’ll study parallel construction in the eBook Developing a Powerful Writing Style, I must introduce the concept here, for producing a parallel series requires the use of two of the conjunctions we just discussed: coordinating conjunctions and correlative conjunctions.

Basically, to follow the rule, you must make certain each element in the series joined with a conjunction satisfies two conditions:

1. Each element appears in the same grammatical form.
2. Each element performs the same grammatical function.

In the above discussion on coordinating conjunctions, I provided some examples of parallel structure. Here they are again. Notice how I double or triple (1) entire sentences, (2) dependent that clauses, (3) adverbial clauses, (4) prepositional phrases, (5) subjects, (6) verbs, and (7) verbal objects. The list of possibilities could go on and on.

Structures Joined Conjunction Example
1. Two sentences and John hit the ball, and he ran to first base.
2. Two dependent that clauses and The book that you enjoyed and that won the award has finally arrived at the store.
3. Two adverbial clauses and He enjoyed the movie because his favorite actor starred and because the special effects required  computer technology.
4. Three prepositional phrases but John hit the ball over the pitcher’s  head, between the legs of the short stop, but into the waiting glove of the outfielder.
5. Two subjects and Lincoln and Jefferson rank among our greatest presidents.
6. Two verbs but Lucy waited for two hours but then decided to leave.
7. Two direct objects or Lucy wants the apple or the orange


Correlative Conjunctions and Parallel Structure

The rule of parallel construction creates a trap for unwary writers trying to use correlative conjunctions. As shown above, these words come in pairs

Correlative Conjunctions

either . . . or
neither . . . nor
not . . . but
not only . . . but (also)
both . . . and

To use them correctly, you must ensure that the structure joined by the first word of the pair is a grammatical mirror image of the structure joined by the second word of the pair.

Not Only - But Also Mistakes

If you want to use the not only . . . but (also) correlative conjunction, you should follow this model:

not only X but (also) Y
X = Y (in grammatical function)
X = Y (in grammatical form)

The key lies in the placement of the words. Carefully line up the first structure after the words not only and then the second structure performing the same grammatical function immediately after the but or but also. Check out these four examples:

1. not only [noun acting as subject] but [noun acting as subject]

Not only the CEO but the entire Board of Directors attended the press conference.

2. not only [verb] but also [verb]

The reporter not only contacted her sources but also spent many hours in the library.

3. not only [prepositional phrase] but [prepositional phrase]

He retraced his steps not only along the trail but throughout the camp.

4. not only [entire sentence] but [entire sentence]

Not only did the court reverse the lower court, but it sent a message to the police.

In the final example, when you use correlative conjunctions to join entire sentences, you’ll have to use an auxiliary verb with the first sentence (did) and invert it, placing the subject between the auxiliary (did) and the main verb (reverse) (not only did the court reverse . . . ). If you wrote the following, you would produce a nonparallel construction:

The court not only reversed the lower court, but it sent a message to the police.

Here the not only joins just the verb (reversed) while the but joins an entire independent clause (it sent). Remember the formula X = Y. Here, “verb” does not equal “entire clause.”

Many writers botch the use of correlative conjunctions, making mistakes like this:

Wrong: She not only wanted a hamburger but French fries.
Right: She wanted not only a hamburger but French fries.

In the above example the first part of the pair, not only, joins the verb wanted. But the second part of the pair, but, joins the direct object French fries. The rule of parallel construction forbids the joining of a verb with a noun.

Neither - Nor Mistakes

This rule of parallel construction applies to all the correlative conjunctions. Make sure the structure joined with the first word mirrors the structure joined with the second word.

An example:

Wrong: The coach neither wanted to lose nor to tie.
Right: The coach wanted neither to lose nor to tie.

Either - Or Mistakes

Some examples:

Wrong: Either you must wear your suit or your tux.
Right: Either you must wear your suit, or you must wear your tux.
Right: You must wear either your suit or your tux.


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