9.3 Parallel Structure, Coordination & Subordination

9.3 Parallel Structure, Coordination & Subordination

Quick Answer: When you join ideas in a list or a pair, put them in the same grammatical form—that is parallel structure. Use coordination (FANBOYS, semicolons) for equal ideas and subordination (because, although, when, who…) when one idea should support another. Strong sentence combining creates smooth, logical prose without fragments, run-ons, or mismatched forms.

PERT Writing items often present a sentence with a broken series, a skewed not only…but also pair, or four ways to combine short sentences. Your job is to choose the revision that is grammatical, balanced, and clear.

Parallel Structure Basics

Parallel structure (parallelism) means matching forms for matching roles. If the first item is a noun, the next items should be nouns; if the first is an -ing phrase, keep -ing; if the first is a full clause, continue with clauses.

Lists and Series

• Not parallel: She likes to read, jogging, and weekend hikes.
• Parallel (infinitives): She likes to read, to jog, and to hike on weekends.
• Parallel (gerunds): She likes reading, jogging, and hiking on weekends.
• Parallel (nouns): She enjoys reading, jogging, and weekend hikes.

Any of the parallel versions can be correct; mixing forms in one series is the error.

Paired Ideas and Comparisons

Parallelism also governs pairs linked by and, or, than, or as.

• Not parallel: Writing clearly is as important as to speak confidently.
• Parallel: Writing clearly is as important as speaking confidently.
• Not parallel: She spent more time on practice tests than reviewing explanations.
• Parallel: She spent more time on practice tests than on reviewing explanations. Or: …more time taking practice tests than reviewing explanations.

Correlative Conjunctions (High-Yield)

Correlative pairs work in two halves. Whatever grammatical structure follows the first half must follow the second.

Special care with not only…but also: place not only immediately before the first parallel element, and but also immediately before the second.

• Skewed: She not only finished the reading but also the writing section. (finished ≠ the writing section)
• Balanced: She finished not only the reading section but also the writing section.
• Balanced: She not only finished the reading section but also reviewed her answers.

Verb Forms and Voice

Keep verbals consistent in a series: all infinitives, all gerunds, or all past participles for passive lists.

• Not parallel: The essay was planned, drafted, and they revised it carefully.
• Parallel: The essay was planned, drafted, and revised carefully.
• Parallel (active): They planned, drafted, and revised the essay carefully.

Mixing active and passive inside one series often breaks parallelism and muddies the actor.

Coordination: Joining Equal Ideas

Coordination links ideas of similar importance. Tools include:

• Coordinating conjunctions (FANBOYS: for, and, nor, but, or, yet, so) with a comma between independent clauses
• Semicolons between closely related independent clauses
• Conjunctive adverbs with semicolon + comma (however, therefore, moreover…)
• Simple and/or inside phrases for equal words or phrases

When Coordination Is the Wrong Choice

If one idea is clearly background, cause, or condition, coordination can flatten logic:

• Flatter: The cut score is 103, and she studied grammar for two weeks.
• Clearer subordination: Because the cut score is 103, she studied grammar for two weeks.

PERT “most effective combination” items often reward subordination when the stem shows cause, time, contrast, or condition.

Subordination: Ranking Ideas

Subordination makes one clause dependent so the independent clause carries the main point.

Common subordinators:

• Time: when, while, as, before, after, until, since
• Cause/reason: because, since, as
• Contrast/concession: although, though, even though, whereas, while
• Condition: if, unless, provided that
• Purpose/result: so that, in order that
• Relative: who, whom, whose, which, that

Placement and Punctuation Reminders

• Dependent clause first: comma after it — When the lab opens, students line up.
• Dependent clause second: often no comma for essential info — Students line up when the lab opens.
• Nonessential relative clause: commas — My advisor, who trained at the writing center, suggested drills.
• Essential relative clause: no commas — Students who skip parallel practice miss easy points.

Subordination is not an excuse for fragments: a dependent clause still needs an independent clause in the same sentence.

Combining Sentences Effectively

PERT-style questions may show two or three short sentences and ask for the best combination. Use this decision tree:

1. Are the ideas equal? → Coordinate with FANBOYS or a semicolon; keep forms parallel.
2. Does one idea explain, time, or limit the other? → Subordinate the lesser idea.
3. Can a relative clause or modifier attach cleanly? → Embed detail next to the noun it describes (and avoid danglers).
4. Check the result: no fused sentences, no comma splices, no broken parallelism, no new fragments.

Worked Combinations

Originals:
The PERT Writing section tests grammar. It also tests sentence structure. Many students underestimate both.

• Coordinate + parallel: The PERT Writing section tests grammar and sentence structure, and many students underestimate both.
• Subordinate: Although many students underestimate them, the PERT Writing section tests both grammar and sentence structure.
• Relative embed: The PERT Writing section, which tests grammar and sentence structure, is often underestimated by students.

All three can be correct; choose the option that matches the emphasis the stem requires and stays parallel.

Broken combine (trap):
The PERT Writing section tests grammar, it also tests sentence structure. → comma splice.
Testing grammar and to check sentence structure… → not parallel.

Embedding with Phrases

You can also combine by turning a sentence into a phrase:

• Two sentences: Jordan opened the booklet. Jordan felt calm.
• Participial: Opening the booklet, Jordan felt calm. (subject matches)
• Absolute/with phrase: With the booklet open, Jordan felt calm.
• Appositive: Jordan, a careful test taker, felt calm as she opened the booklet.

Phrase embedding saves words but reintroduces modifier rules: the implied subject of a verbal phrase must match the main subject.

Parallelism + Coordination/Subordination Together

Real items stack skills. Example problem pattern:

Choose the best revision:
The orientation asked students to complete a form, watching a safety video, and that they should tour the lab.

• Diagnosis: series not parallel (infinitive / gerund / clause).
• Strong fix: The orientation asked students to complete a form, watch a safety video, and tour the lab.
• Also possible: …completing a form, watching a safety video, and touring the lab (all gerunds after a suitable lead-in).

Another stacked pattern uses correlatives across clauses:

• Faulty: Not only did she review coordination but also subordination was practiced.
• Parallel: Not only did she review coordination, but she also practiced subordination.
• Parallel (nouns): She reviewed not only coordination but also subordination.

Common PERT Traps in This Skill Cluster

Mini Routine for Test Day

1. Mark the joiners: and, or, but, not only…but also, either…or, commas in a series.
2. Label forms of each listed element (N, V, -ing, infinitive, clause).
3. Force a match in your preferred answer.
4. Check logic: coordination for equals, subordination for ranked ideas.
5. Reread aloud (quietly): mismatched rhythm often signals mismatched grammar.

Parallel structure, coordination, and subordination are the toolkit for mature sentences: equal ideas line up, supporting ideas step back, and nothing dangles or runs on. With clause completeness (9.1) and modifier placement (9.2) already in place, you can revise PERT Writing items toward clear, college-ready English under adaptive testing conditions.