Parallelism

Parallelism refers to the use of identical grammatical structures for related words, phrases, or clauses in a sentence or a paragraph.  

Parallelism can make your writing more forceful, interesting, and clear. It helps to link related ideas and to emphasize the relationships between them. Once a grammatical pattern has been established, the reader doesn’t have to strain to understand your meaning and ideas. Faulty parallelism refers to the absence of parallel structure and the subsequent loss of clarity. 

Parallelism ensures that similar clauses or phrases are uniform in expression and function. To achieve parallelism, you must use the same verb, noun, adverb, or adjective forms consistently throughout a sentence. 

Consider the following examples: 

1. e.g., Paul likes dancing, swimming, and running. 
2. e.g., Paul likes to dance, swimming, and run.

In the first sentence, all of the activities Paul enjoys are consistently presented as gerunds (verbs in their –ing form that act as a noun), which retains parallelism. On the other hand, in the second sentence, the activities Paul enjoys are presented in inconsistent forms, resulting in a sentence that is not parallel. This results in a decreased flow, an awkward sentence, and an increased amount of work for the reader.

For more about gerunds, visit our resource on gerunds and infinitives.

You will encounter many instances where you will need to make sure your sentence is parallel. The most common situations are listed below: 

Lists or Series 

All lists of things, qualities, or actions should take the same grammatical form.  

• Faulty: e.g., Cassandra loves reading the newspaper, taking long walks, and to dance the tango. 
• Parallel: e.g., Cassandra loves reading the newspaper, taking long walks, and dancing the tango. 

Note that you can create parallel structure in various ways: 

• e.g., For opera to take root in Great Britain, infrastructure was required: the building of financial support, the training of singers, and the education of audiences. 
• e.g., For opera to take root in Great Britain, three things were required: building financial support, training singers, and educating audiences. 
• e.g., For opera to take root in Great Britain, it was necessary to build financial support, train singers, and educate audiences. 

When a list begins with a preposition, either include the preposition only at the beginning of the list or include it before every item: Dictionaries are useful for learning to spell correctly and to prop open windows (Incorrect). Dictionaries are useful for learning to spell correctly and propping open windows (Correct).

• Faulty: e.g., Among many cultures, rites of passage can involve feats of courage and sometimes even doing dangerous things. 
  • The addition of the verb doing before the second noun disrupts the balance of the sentence. 
• Parallel: e.g., Among many cultures, rites of passage can involve feats of courage and sometimes even dangerous things. 

Phrases Joined by Correlative Conjunctions 

Phrases Joined by Correlative Conjunctions: (either...or, neither...nor, both...and, not only...but also, whether...or, etc.). 

• Faulty: e.g., Idrees is not only fluent in Urdu but also in English. 
• Parallel: e.g., Idrees is fluent not only in Urdu but also in English. 

Since both nouns are modified by a single adjective (fluent), the adjective should be placed before the first correlative conjunction (not only). 

Where each correlative conjunction has its own verb, the correlative conjunction comes before the verb: 

• Faulty: e.g., Idrees speaks not only two languages fluently but also plays cricket very well. 
• Parallel: e.g., Idrees not only speaks two languages fluently but also plays cricket very well.

Sentences that Explain Chronological Events 

Sentences must use verb tenses that are consistent and reflect the chronological order of events. 

• Faulty: e.g., Kevin stopped asking for directions and starts using a map. 
• Parallel: e.g., Kevin stopped asking for directions and started using a map. 

Because this sentence describes an event that happened in the past, both verbs need to be in the past tense. 

Using Parallelism to Remove Repetition   

Repetitive words can often be removed from a sentence if their removal does not detract from your clarity. 

• Example 1
  • Faulty: e.g., Alan picked up his computer. Alan picked up his books. Alan picked up his phone. 
  • Parallel: e.g., Alan picked up his computer, books, and phone.
• Example 2
  • Faulty: e.g., In the morning, afternoon, and the evening... 
  • Parallel: e.g., In the morning, afternoon, and evening... 

Using Parallelism to Increase Clarity

• Faulty: e.g., Sandra is interested in Canadian art and poetry. 
  • In this example, we’re not sure if Sandra is interested in Canadian poetry specifically or poetry in general. To ensure your meaning is clear, repeat ‘Canadian’ and retain parallelism. 
• Parallel: e.g., Sandra is interested in Canadian art and Canadian poetry.