2.3 Sentence Structure, Run-Ons, Fragments & Parallelism

Sentence Structure, Run-Ons, Fragments & Parallelism

A mastery of sentence architecture is essential for scoring high on the ACET English Proficiency test. Questions in the Written Expression and Sentence Correction sections frequently assess your ability to recognize structural defects—such as sentence fragments, run-on sentences, and comma splices—and enforce strict grammatical parallelism.

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1. Clause Architecture and Sentence Types

Understanding sentence structure begins with distinguishing between independent clauses and dependent (subordinate) clauses.

• Independent Clause: Contains a subject and a verb and expresses a complete thought. It can stand alone as a sentence.
  • Example: The laboratory director reviewed the clinical trial results.
• Dependent Clause: Contains a subject and a verb but begins with a subordinating conjunction (because, although, since, while, unless, if, whereas) or relative pronoun (who, which, that). It cannot stand alone.
  • Example: ...because the clinical trial results were inconclusive.

The Four Fundamental Sentence Structures

1. Simple Sentence: One independent clause ("The engine started.").
2. Compound Sentence: Two or more independent clauses joined by a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so) preceded by a comma, or by a semicolon ("The engine started, and the vehicle accelerated.").
3. Complex Sentence: One independent clause combined with at least one dependent clause ("When the ignition turned, the engine started.").
4. Compound-Complex Sentence: At least two independent clauses and at least one dependent clause ("When the ignition turned, the engine started, and the vehicle accelerated down the track.").

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2. Sentence Fragments

A sentence fragment is a group of words punctuated as a full sentence, but lacking an independent clause. ACET questions disguise fragments by introducing long modifying clauses or verbal phrases.

Typical ACET Fragment Structures

1. Subordinate Clause Fragments:
   • Fragment: Although the engineering team spent months refining the prototype aerodynamic design.
   • Correction: Although the engineering team spent months refining the prototype aerodynamic design, they failed to resolve the overheating issue.
2. Participial Phrase Fragments:
   • Fragment: Having analyzed the macroeconomic indicators and conducted extensive market research across several provinces.
   • Correction: Having analyzed the macroeconomic indicators and conducted extensive market research across several provinces, the economists published their forecast.
3. Relative Clause Fragments:
   • Fragment: Which explains why the financial auditors requested additional documentation from the accounting department.
   • Correction: The discrepancy in revenues was significant, which explains why the financial auditors requested additional documentation.

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3. Run-On Sentences and Comma Splices

A run-on sentence occurs when two independent clauses are joined without adequate punctuation or coordinating conjunctions.

• Fused Sentence (No punctuation): The storm damaged the power lines the neighborhood was without electricity for three days.
• Comma Splice (Comma without conjunction): The storm damaged the power lines, the neighborhood was without electricity for three days.

Four Standard Methods to Repair Run-Ons & Comma Splices

ACET Trap Notice: Words like however, therefore, furthermore, nevertheless, moreover, consequently, and meanwhile are conjunctive adverbs, not coordinating conjunctions. Joining two independent clauses with only a comma and however creates a comma splice!

• Incorrect: The experiment succeeded, however, the results were not published.
• Correct: The experiment succeeded; however, the results were not published.

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4. Grammatical Parallelism

Parallelism (parallel structure) requires that elements in a series, list, or paired comparison share the same grammatical form. Parallel structure creates clarity, balance, and rhythm.

Items in a Series

All items in a list must be grammatically equivalent (all nouns, all gerunds, all infinitives, or all prepositions).

• Non-Parallel: The internship program emphasizes developing leadership skills, the mastery of project management, and to communicate effectively.
• Analysis: developing (gerund), the mastery (noun phrase), to communicate (infinitive clause). Unbalanced!
• Parallel: The internship program emphasizes developing leadership skills, mastering project management, and communicating effectively.

Parallelism with Correlative Conjunctions

When using paired conjunctions—either...or, neither...nor, not only...but also, both...and, whether...or—the grammatical structure following the first element must mirror the structure following the second.

• Non-Parallel: The chief executive officer not only commended the software developers for their dedication but also the financial analysts.
• Analysis: Not only is followed by a verb phrase (commended the software developers...), whereas but also is followed by a noun phrase (the financial analysts).
• Parallel: The chief executive officer commended not only the software developers for their dedication but also the financial analysts.

Parallelism in Comparisons (Than / As)

When making comparisons using than or as, ensure that you are comparing equivalent entities and that the structures match.

• Illogical/Non-Parallel: The architectural design of the new library is far more modern than the old administration building.
• Analysis: Compares the design (an abstract concept) directly to the building (a physical structure).
• Parallel: The architectural design of the new library is far more modern than that of the old administration building. (Where that stands for the design).