Purpose
By the end of this lesson, you will be able to identify and correct faulty parallel structure in lists, comparisons, and paired constructions.Lesson Explanation
Parallel structure requires that grammatically similar elements — in a list, a comparison, or a pair joined by a coordinating conjunction (Part 1, Lesson 5) — share the same grammatical form. In a list, all items should share the same part of speech or verb form: “She likes hiking, swimming, and to bike.” is faulty (two gerunds, from Part 2, Lesson 5, mixed with one infinitive) — the corrected version keeps all three parallel: “She likes hiking, swimming, and biking.” or “She likes to hike, to swim, and to bike.” Parallel structure also applies to paired correlative conjunctions like “either…or,” “neither…nor,” and “not only…but also” — the grammatical structure following each half must match: “She not only enjoys reading but also to write.” is faulty; “She not only enjoys reading but also enjoys writing.” or more concisely “She enjoys not only reading but also writing” is correctly parallel. Faulty parallelism is a genuinely common, subtle error precisely because each individual piece of the sentence may be grammatically fine on its own — the problem only appears when comparing the pieces to each other. A reliable check: isolate each item in the list or each half of the paired structure, and confirm they could each substitute into the same surrounding sentence frame using the identical grammatical form.Practice Questions
1. What does parallel structure require?
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That grammatically similar elements share the same grammatical form.2. Is “She likes hiking, swimming, and to bike” correctly parallel?
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No — it mixes gerunds with an infinitive.3. Write a corrected, fully parallel version of that sentence.
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She likes hiking, swimming, and biking. (or: She likes to hike, to swim, and to bike.)4. Name one pair of correlative conjunctions that require parallel structure.
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Either…or, neither…nor, or not only…but also.5. Is “She not only enjoys reading but also to write” correctly parallel?
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No.6. Write a corrected, fully parallel version of that sentence.
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She not only enjoys reading but also enjoys writing. (or: She enjoys not only reading but also writing.)7. Why is faulty parallelism a genuinely subtle error?
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Because each individual piece may be grammatically fine on its own; the problem only shows up in comparison.8. What is a reliable check for parallel structure?
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Isolating each item and confirming they could substitute into the same sentence frame using the identical grammatical form.9. What earlier-covered grammatical form is relevant to the “hiking/swimming/to bike” example?
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Gerund phrases (Part 2, Lesson 5).10. Does parallel structure apply only to lists, or also to paired constructions and comparisons?
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It applies to all three.11. What earlier lesson introduced the coordinating conjunctions relevant to parallel lists?
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Part 1, Lesson 5.12. Is “She enjoys not only reading but also writing” a correctly parallel sentence?