9.3 Sentence Structure & Syntactic Control

Sentence Structure & Syntactic Control on the Stanford 10

Quick Summary: Sentence Structure is the largest Language Expression cluster on Stanford 10 (9 of 24 Expression items on a real Intermediate 2 report). Pearson places it in the second section of the Traditional Language subtest. The Arkansas guide says lower levels test run-ons, fragments and awkward construction, while higher levels add the subtleties of sentence formation. These questions check whether students can judge sentence boundaries, clause relationships and parallel structure. Core tested concepts include categorizing sentences into the four classical structural types, identifying and eliminating fragments and comma splices, repositioning misplaced and dangling modifiers, and maintaining rigorous parallel structure across series and paired correlative conjunctions.

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Clause Analysis: Independent versus Dependent (Subordinate)

At the core of syntactic control is the ability to parse clauses. A clause is a grammatical unit containing both a subject and a predicate (verb). Understanding how clauses connect distinguishes proficient writers on the Stanford 10.

1. Independent Clauses

An independent clause (or main clause) contains a subject and a verb and expresses a complete, standalone thought. It can exist independently as a simple sentence:

INDEPENDENT: The seismic sensors detected a minor tremor near the volcanic caldera.

2. Dependent (Subordinate) Clauses

A dependent clause contains a subject and a verb but begins with a subordinating word that creates an incomplete semantic unit. It cannot stand alone and depends on an independent clause for syntactic completeness. Dependent clauses fall into three primary categories:

1. Adverbial Clauses: Introduced by subordinating conjunctions (after, although, as, because, before, if, since, unless, until, when, whenever, where, while). They modify verbs, adjectives, or adverbs by expressing time, cause, condition, or concession.
   • Example: Although the atmospheric pressure dropped dramatically, the barometric readings stabilized.
2. Adjectival (Relative) Clauses: Introduced by relative pronouns (who, whom, whose, which, that). They modify a preceding noun or pronoun.
   • Essential (Restrictive): The technician who calibrated the spectrograph verified the data.
   • Nonessential (Nonrestrictive): The Hubble Space Telescope, which was deployed in 1990, transformed astrophysics.
3. Noun Clauses: Introduced by words like that, what, whatever, who, whoever, how, or why. They function syntactically as subjects, direct objects, or predicate nominatives within the main clause.
   • Example: The marine biologists discovered that the coral reef was recovering.

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The Four Classical Sentence Structures

Students should be able to recognize four sentence structures:

Compound vs. Simple Sentence Distractor

A recurring distractor is mislabeling a simple sentence with a compound predicate as a compound sentence. A compound sentence must contain two distinct independent clauses, each with its own expressed subject:

SIMPLE (Compound Predicate):   The spacecraft entered orbit and deployed its solar panels.
                               (One subject: spacecraft; two verbs: entered, deployed)

COMPOUND (Two Clauses):         The spacecraft entered orbit, and its robotic arm deployed the solar panels.
                               (Two distinct subjects: spacecraft, arm)

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Identifying and Remediating Sentence Fragments

A sentence fragment is an incomplete construction punctuated as though it were a complete sentence. A fragment lacks a subject, lacks a finite predicate, or is an orphaned dependent clause.

1. The Missing Subject Fragment

FRAGMENT:   Analyzed the chemical composition of the core samples in the mobile laboratory.
CORRECTION: The research team analyzed the chemical composition of the core samples in the mobile laboratory.

2. The Verbal / Incomplete Predicate Trap

Fragment items often disguise the problem with verbal phrases—participles ending in -ing or -ed, or infinitives beginning with to—without a true finite main verb:

FRAGMENT:   The agricultural engineers experimenting with drought-resistant wheat strains in arid regions.
            (The word 'experimenting' is a present participle acting as an adjective; there is no main verb.)
CORRECTION: The agricultural engineers experimented with drought-resistant wheat strains in arid regions.
CORRECTION: The agricultural engineers are experimenting with drought-resistant wheat strains in arid regions.

3. The Orphaned Subordinate Clause

A dependent clause cannot stand alone, even if it contains a subject and a verb:

FRAGMENT:   Since the deep ocean currents regulate global weather patterns across the hemispheres.
CORRECTION: Since the deep ocean currents regulate global weather patterns across the hemispheres, oceanographers monitor marine temperatures continuously.

4. Appositive and Prepositional Phrase Fragments

FRAGMENT:   A groundbreaking discovery that earned the team international acclaim in physics.
CORRECTION: The team announced a groundbreaking discovery that earned them international acclaim in physics.

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Run-On Sentences and Comma Splices: Three Core Corrections

A run-on sentence occurs when two or more independent clauses are joined without adequate punctuation or conjunctions. There are two primary types:

1. Fused Sentence: Two independent clauses run together with no punctuation whatsoever.
2. Comma Splice: Two independent clauses joined only by a comma without a coordinating conjunction.

$\text{COMMA SPLICE: } \text{Independent Clause } \mathbf{,} \text{ Independent Clause} \quad (\text{INCORRECT})$

COMMA SPLICE: The geothermal plant generates clean electricity, it supplies power to forty thousand households.

To repair a comma splice or run-on, use one of three standard correction methods (plus subordination):

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Modifiers: Misplaced versus Dangling

Modifiers must clearly and logically point to the specific word they modify. Modifiers placed incorrectly distort meaning or create unintentional absurdity.

1. Misplaced Modifiers

A misplaced modifier is separated from the word it modifies, appearing to describe the wrong noun:

MISPLACED:  Soaring high above the snow-capped mountain peaks, the climbers spotted a golden eagle.
            (Literally says the climbers were soaring above the peaks!)
CORRECTED:  The climbers spotted a golden eagle soaring high above the snow-capped mountain peaks.
CORRECTED:  Soaring high above the snow-capped mountain peaks, a golden eagle was spotted by the climbers.

2. Dangling Modifiers

A dangling modifier begins a sentence with a descriptive verbal phrase, but the noun intended to be modified is completely missing from the sentence. The phrase incorrectly attaches to whatever noun immediately follows the comma:

DANGLING:   Having completed the complex orbital calculations, the telescope was pointed toward Jupiter.
            (The telescope cannot calculate orbits!)
CORRECTED:  Having completed the complex orbital calculations, the astronomer pointed the telescope toward Jupiter.

Diagnostic Test for Dangling Modifiers: Look at the introductory participial or prepositional phrase. Ask: Who or what is performing this action? The logical actor must be the grammatical subject immediately following the comma.

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Parallel Structure (Parallelism)

Parallelism requires that coordinate elements in a sentence share the same grammatical form. Parallel structure creates rhythm, balance, and clarity.

1. Parallelism in Lists and Series

All elements in a series must belong to identical grammatical categories (all nouns, all gerunds, all prepositional phrases, or all verbs in matching tense):

NONPARALLEL: The robotic vehicle's duties include collecting soil samples, analyzing rock strata, and to transmit data.
PARALLEL:    The robotic vehicle's duties include collecting soil samples, analyzing rock strata, and transmitting data.

NONPARALLEL: The student demonstrated diligence, patience, and was acting creatively.
PARALLEL:    The student demonstrated diligence, patience, and creativity.

2. Parallelism with Correlative Conjunctions

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

NONPARALLEL: The architect not only designed the civic center but also the historic museum was renovated by him.
PARALLEL:    The architect not only designed the civic center but also renovated the historic museum.

NONPARALLEL: Students should either register for the morning session or they should choose the afternoon workshop.
PARALLEL:    Students should register either for the morning session or for the afternoon workshop.