23. Parallel Structure

Overview

Clear, professional writing depends on consistent grammatical patterns within sentences. This chapter examines the principle of parallelism—how aligning the forms of connected words, phrases, and clauses strengthens both readability and style. Readers will explore how this concept applies across conjunctions, lists, and comparisons. By the end, writers will be equipped to identify and correct structural imbalances in their own work.

Definition

Parallelism is the practice of giving two or more related grammatical elements the same structural form within a sentence. Whenever words, phrases, or clauses are coordinated or listed together, using a consistent grammatical pattern—all nouns, all infinitives, all gerunds, or all clauses of the same type—prevents reader confusion and creates a sense of balance and coherence.

Key Rules

  1. 1. Coordinating Conjunctions and Balance

    Coordinating conjunctions such as 'and', 'but', 'or', and 'nor' link elements that must share identical grammatical categories. A noun must be paired with another noun, a verb form with the same verb form, and an adjective with another adjective—mismatched forms produce awkward or unclear sentences.

    Show example Example

    The seminar was informative and thought-provoking.

  2. 2. Symmetry with Correlative Conjunctions

    Paired conjunctions—'both...and', 'either...or', 'neither...nor', and 'not only...but also'—demand that identical grammatical structures follow each element of the pair. Whatever grammatical form appears after the first conjunction must be mirrored after the second.

    Show example Example

    She was not only praised for her research but also admired for her presentation skills.

  3. 3. Uniformity in Series and Lists

    Every item within a series or bulleted list must conform to the same grammatical pattern. If the first item is a noun, every subsequent item must also be a noun; if the first item is an infinitive phrase, all items must be infinitive phrases.

    Show example Example

    The workshop covered managing time effectively, setting measurable objectives, and evaluating personal progress.

  4. 4. Parallelism in Comparative Structures

    Comparisons using 'than' or 'as...as' require that the elements being placed in comparison have matching grammatical forms. Pairing an infinitive against a gerund, or a clause against a phrase, makes the comparison structurally uneven.

    Show example Example

    Finishing a marathon is as demanding as completing a grueling mountain hike.

  5. 5. Consistency of Gerunds and Infinitives

    When enumerating a series of actions, commit exclusively to either the gerund form or the infinitive form throughout the entire list. Alternating between '-ing' gerunds and 'to + verb' infinitives within the same sequence disrupts grammatical balance.

    Show example Example

    The intern was responsible for organizing files, scheduling appointments, and drafting correspondence.

  6. 6. Structural Alignment of Clauses

    Joined clauses should share the same structural pattern—both active, both passive, or both following the same type of subordinate construction. Switching between structural patterns mid-sentence creates an inconsistency that can confuse readers.

    Show example Example

    The agreement was signed by the client and was witnessed by the notary.

Example Sentences

  1. Example 1

    The athlete spent the off-season lifting weights, studying game footage, and refining her technique.

    Why this works

    Illustrates three parallel gerund phrases within a single series.

  2. Example 2

    To complete the internship, participants must attend all sessions, submit weekly reflections, and pass a final evaluation.

    Why this works

    Shows parallel base-verb phrases all dependent on the auxiliary 'must'.

  3. Example 3

    The revised policy is not only more transparent but also considerably fairer to all employees.

    Why this works

    Demonstrates parallel adjective phrases joined by the correlative pair 'not only...but also'.

  4. Example 4

    The committee agreed that the venue should be accessible and that the program should start on time.

    Why this works

    Highlights two parallel noun clauses both introduced by 'that'.

Common Errors

  • She enjoys jogging, to cycle, and swimming.

    She enjoys jogging, cycling, and swimming.' or 'She enjoys to jog, to cycle, and to swim.

    Why?

    Mixing gerunds and infinitives within a single list, for example

  • He not only cooks well but also is a great baker.

    He is not only a great cook but also a great baker.' or 'He not only cooks well but also bakes well.

    Why?

    Placing correlative conjunctions so that different grammatical forms follow each element, for example

  • To jog every morning is healthier than spending your day on the couch.

    Jogging every morning is healthier than spending your day on the couch.

    Why?

    Comparing an infinitive phrase to a gerund phrase, for example

  • The role demands punctuality, being honest, and hard work.

    The role demands punctuality, honesty, and hard work.

    Why?

    Including items of different parts of speech in a list, for example

Key Takeaways

  • Use matching grammatical forms whenever elements are linked by coordinating conjunctions such as 'and', 'but', or 'or'.
  • Correlative conjunction pairs—'both...and', 'either...or', 'not only...but also'—must be followed by structurally identical elements.
  • Every item in a series or list must share the same grammatical category or construction.
  • Comparisons using 'than' or 'as...as' require structurally equivalent elements on both sides.
  • Never alternate between gerunds and infinitives when listing actions within the same sentence.
  • Clauses joined within a sentence should maintain a consistent voice and structural pattern throughout.
  • Parallelism applies equally at the level of individual words, multi-word phrases, and full clauses.
  • Reviewing for parallel structure is a key step in editing any formal or professional piece of writing.

Practice - Set 1

  1. Our new manager prefers to set clear goals, to communicate openly, and _____.

  2. The candidate was selected not only for her extensive experience _____ for her exceptional communication skills.

  3. Many people find that cycling to work is healthier than _____.

  4. Identify the sentence that displays correct parallel structure.

  5. Either we must invest in modernizing our equipment _____ we must accept lower production rates.

  6. The job description states that the ideal candidate must possess integrity, adaptability, and _____.

  7. Neither the team leader nor _____ for the project delay.

Practice - Set 2

  1. Public speaking can be as terrifying as _____ in front of a camera.

  2. The professor advised us to read the article carefully, _____ the primary arguments, and write a summary.

  3. The artist was praised both for her innovative style _____ her meticulous attention to detail.

  4. Which sentence correctly uses parallel structure with a correlative conjunction?

  5. The coach told the players to arrive early, _____ their equipment, and stay focused throughout the game.

Live speaking practice

Speak it out: Parallel Structure

You are in a project kickoff meeting at a technology firm in Bengaluru. You are presenting your team's quarterly plan and resource requirements to your detail-oriented senior manager.

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