Parallelism and Parallel Structure — Definition & Examples

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Parallelism-and-Parallel-Structure-Definition

Here, we explain parallel structures and their correct usage in written and spoken English. Using parallelism will improve your writing by enhancing its clarity and credibility.

Parallelism and Parallel Structure – In a Nutshell

  • Using parallelism increases the readability of your written work. Readers will be able to follow the word patterns with ease.
  • You create a parallel construction by following the same grammatical pattern in each idea or compared item in your sentence.
  • When we use non-parallel elements in a sentence, they create a jarring effect.1 The result can lack emphasis and meaning. We call this type of error faulty parallelism.

Definition: Parallelism and parallel structure

Parallelism involves repeating a chosen grammatical form within a sentence. According to Cambridge English, it is an organizational pattern and a less obvious way to achieve connections within sentences and beyond.

Common types of parallelism used in academic writing include pairs or series, in addition to parallel outlines and headings.2

Parallelism in a series

A series is three or more contiguous elements. We use commas to punctuate each component and – sometimes – before the coordinating conjunction. The last element connects to the previous ones with a coordinating conjunction: and, or, but (not) or (not) yet.

Nouns should go together in parallel and – similarly – adjectives appear alongside other adjectives.3 In contrast, a series where the components are in a different format may sound awkward and need clarification.

Parallel structure of words

Parallel words use the same patterns to show that two or more ideas are as important as each other. Let’s consider some examples.

Example of parallel sturcture of words:

Non-Parallel The survey respondents answered questions about communication, negotiation and working as a team.

The manager wrote his report quickly, accurately and in detail.

We are seeking applicants who are honest, punctual and work hard.
Parallel The survey respondents answered communication, negotiation and teamwork questions.

The production manager wrote his report quickly, accurately and thoroughly.

We are seeking applicants who are honest, punctual and hard-working.

Parallel structure of phrases

Like words, parallel phrases use the same grammatical structure. For instance, mixing verb phrases with noun phrases is considered a parallelism error. Likewise, when the series consists of several verb forms, we should not mingle the forms, i.e. gerunds (-ing form) with infinitives (starting with ‘to’).

Example of parallel structure of phrases:

Non-Parallel This research program aims to contact participants, collect data and answering the research questions.
Parallel This research program aims to contact participants, collect data and answer the research questions.

Parallel structure of clauses

Similarly, clauses within sentences benefit from parallel structures. As an example, prepositional phrases ought to be uniform. Let’s consider some more examples.

Example of parallel structure of clauses:

Non-Parallel He climbed the wall and onto the roof.(without preposition)
Parallel He climbed up the wall and onto the roof.(with preposition)

Parallel structure after colons

After a colon, keep all listed elements in the same form.

Example of parallel after colons:

Non-Parallel Dictionaries contain helpful information: word meanings, pronunciations, spellings and looking up irregular verbs.
Parallel Dictionaries contain helpful information: word meanings, pronunciations, spellings and irregular verb tables.

Parallelism in pairs

Pairs are connected ideas in a sentence. Next, we will consider how to use coordinating conjunctions – such as ‘for’, ‘and’, ‘or’, ‘but’, ‘so’, ‘nor’, and ‘yet‘ – to join parallel pairs.4

Example of parallelism in pairs:

Non-Parallel My friends took the new student ice skating and to the Italian restaurant.

Edward likes hiking, hillwalking and to climb mountains.

I am deciding whether to ride my bicycle, take the bus or sharing a lift to work.
Parallel My friends took the new student to the ice rink and the Italian restaurant.

Edward likes hiking, hillwalking and climbing mountains.

I am deciding whether to ride my bicycle, take the bus or share a lift to work.

Similarly, the next examples show how the correlative conjunctions – a type of connecting structure – also benefit from parallelism:

  • Not only…but also.
  • Either…or.
  • Neither…nor.

Example of parallelism in conncting structures:

Non-Parallel My cousin not only likes watching football but also to play golf.

The researchers collected the information by either using an online survey or phone interviews.
Parallel My cousin not only likes watching football but also playing golf.
or
My cousin not only likes to watch football but also to play golf.

The researchers collected the information (either) through an online survey or phone interviews.
or
The researchers collected the information using online surveys or phone interviews.

Additionally, we can use parallel comparatives with ‘over’, ‘than’ and ‘as’.

Example of parallel comparatives:

Non-Parallel He prefers to watch a film at home over going to the cinema.

He said he would rather look for a job than starting a business.
Parallel He prefers watching films at home over going to the cinema.

He said he would rather look for a job than start a business.

Parallelism in outlines and headings

An outline should have a balanced structure that uses parallelism and coordination principles. Usually, nouns ought to be parallel with nouns, verb forms with verb forms, adjectives with adjectives and so on.

Another consideration in outlines is that items of equal significance should have similar numeral or letter designations, i.e., consistent value or weighting.

Example of parallelism in connecting structures:

INCONSISTENT PARALLEL with PROPER COORDINATION
A. Producer-led theories of consumption
B. Adorno and Horkheimer
C. Life-cycle hypothesis.
A. Producer-led theories of consumption
B. Consumer-led theories of consumption
C. Reciprocal models of consumption

FAQs

Parallel structure is when two or more ideas use the same word patterns to show equal importance.

The structure connects ideas logically. Therefore, using parallelism in your writing will help clarify your self-expression and could increase readers’ delight.

Generally, yes. However, logical and clear writing takes priority in the few cases where flexibility with nouns and gerunds becomes necessary. Reasonableness is preferable to rigidity.

Sources

1 Hull University. “Grammar resource: Non-parallel structure.” October 21, 2022. https://libguides.hull.ac.uk/grammar/non-parallelstructure.

2 Learn English Grammar. “Parallel-Structure: Definition & Examples.” Accessed December 13, 2022. https://www.learngrammar.net/english-grammar/parallel-structure.

3 Benner, Margaret L. “Self Teaching Unit: Parallel Structure.” Towson University, 2004. https://webapps.towson.edu/ows/moduleparallel.htm.

4 Purdue Online Writing Lab. “Parallel Structure.” Purdue University. Accessed December 13, 2022. https://owl.purdue.edu/owl/general_writing/mechanics/parallel_structure.html.