Parallel Sentence Struture

Parallel structures are a particularly powerful way to communicate information because they create structural repetitions that emphasize and connect ideas. In grammatical terms, two structures are parallel if they have the same grammatical form (both verbs or both nouns, for example). These parallel items or ideas are often coordinated as items in a list.

Identifying lists that are not presented in parallel is much more difficult for writers than for the readers of their work. Writers know how their ideas relate and tend not to notice when points are not parallel. Without parallel structures, readers may fail to recognize how ideas connect and may be confused by what they read. The following diagram illustrates the patterns for parallel sentence structure.


 
Coordinators in Parallel Structure

Ideas within sentences that are joined by coordinating conjunctions (and, but, or, nor, for, yet, or so) must also be parallel. For example, gadgets and gizmos are joined by coordinating conjunctions in each of the following phrases. These structures are appropriately parallel because the items coordinated are the same part of speech (i.e., gadgets and gizmos are both nouns):

both gadgets and gizmos
not gadgets, but gizmos
neither gadgets nor gizmos
either gadgets or gizmos

The following lists the most commonly used ways of indicating that two or more ideas are coordinated. When these coordinators appear in a sentence, the pairs or lists of items they connect must have the same grammatical form.

  • and

  • or

  • as well as

  • rather than

  • neither... not

  • either... or

  • not only... but also

 
Some Pointers
  1. Use the same verb form when linking ideas together using a coordinating conjunction.

  2. Split excessively long sentences in two to avoid parallelism problems.

  3. Repeat prepositions in lengthy prepositional phrases.

  4. Try to balance length as well as structure.

  5. Ensure lists are parallel by starting all items with nouns or verbs.

  6. Avoid mixing complete sentences and sentence fragments in lists.

  7. Beware of Microsoft’s automated features!

 
Start Exercise

Do you see or hear a problem in the following original example?


Hint
1. Original:
  • repair our existing PCs
  • purchase 11 more hard drives
  • security is insufficient
  • expand our operating hours

1.Hinted:
  • repair our existing PCs
  • purchase 11 more hard drives
  • security is insufficient
  • expand our operating hours

1. Revised:

Explanation

As you probably noted, the items in the original list are expressed inconsistently. While the first, second, and fourth items begin with verbs, the third begins with a noun. The list becomes parallel when the third item is revised so that it also begins with a verb.


If the structures in a list or on either side of the coordinators do not share the same grammatical structure, readers will have difficulty making sense of what is written. To find problems with parallelism, read what you have written out loud. Your ears are much more practiced at finding this sort of problems than your eyes. To help your eyes recognize problems with parallel structure, in the following example we have emphasized relevant coordinating connectors and the first few words of the structures that should be parallel.


Hint
2. Original:

The system survey report will describe, in general, the current system activities, the problems that the current system is experiencing, and to present options and make recommendations to you and other decision making authorities.

2. Hinted:

The system survey report will describe, in general, the current system activities, the problems that the current system is experiencing, and to present options and make recommendations to you and other decision making authorities.

2. Revised:

Explanation

Note that this example appears to present a list of three items: the current system, the problems, and to present options. In this case, however, the writer expected us to make a different connection. The writer intended us to read that the report describes activities and problems and presents options and makes recommendations. Creating two sentences clarifies this intended connection with minimal revision.


The following example also suffers from faculty parallelism:

Hint
3. Original:

This discussion prompted me to contact PTE for further information and the support package that PTE can offer for PC/FOCUS.

3. Hinted:

This discussion prompted me to contact PTE for further information and the support package that PTE can offer for PC/FOCUS.

3. Revised:

Explanation

Did you have difficulty making sense of the original sentence on first reading? Read the original sentence once more and then solution.


To make the sentence clearer on a first reading, we repeated the preposition: for information and for the support package. Repeating prepositions (for, in, of, by, etc.) at the beginning of coordinated phrases both clarifies and emphasizes connections.


As well, we shortened the phrase after the and by creating a short noun string (PC/FOCUS support package). This change helps balance the structure.

Hint
4. Original:

The purpose of this paper is to critique our current project management structure. This critique will discuss the following topics:

  • My vision of the company as an optimal organization.
  • The strengths and weakness of current practices.
  • The effects of the current structure on projects, the employees, and the organization as a whole.
  • Finally, I will recommend ways to improve our structure and bring us closer to our mission.

4. Hinted:

The purpose of this paper is to critique our current project management structure. This critique will discuss the following topics:

  • My vision of the company as an optimal organization.
  • The strengths and weakness of current practices.
  • The effects of the current structure on projects, the employees, and the organization as a whole.
  • Finally, I will recommend ways to improve our structure and bring us closer to our mission.

4. Revised:

Explanation

As you should have noticed, the only change we made in revising was to make the final point a separate sentence, rather than part of the list. The first three points list the three topics for discussion in point form. The original last point is not only a complete sentence, but also the content is not coordinated with the other points. It points to recommendations drawn from a discussion of the three topics rather than to another topic. (Note that this sentence may have been added to the list by mistake when the writer forgot to turn off the bulleted list feature in Microsoft Word.)