Faulty Sentence Structure
Sentence Fragments
A sentence fragment is an incomplete sentence that lacks a subject, a verb, or a complete thought. Every grammatical sentence needs at least one independent clause — a group of words with a subject and a verb that can stand alone. A fragment fails this test because it is missing one of these essential elements or because it begins with a subordinating conjunction and is never attached to an independent clause.
Missing subject: "Walked to the store." — who walked? No subject.
Missing verb: "The tall man in the corner." — no action or state verb.
Subordinate clause standing alone: "Because she was tired." — a dependent clause that needs an independent clause to complete it.
Phrase treated as a sentence: "Running through the park at sunset." — a participial phrase with no main clause.
There are three standard ways to fix a sentence fragment: attach it to an adjacent independent clause, add the missing subject or verb, or remove the subordinating conjunction that makes the clause dependent.
Attach to a main clause: "Because she was tired. She went to bed early." → "Because she was tired, she went to bed early."
Add the missing element: "Walked to the store." → "He walked to the store."
Remove the subordinator: "Because she was tired." → "She was tired."
Run-On Sentences
A run-on sentence occurs when two or more independent clauses are joined without proper punctuation or an appropriate coordinating conjunction. There are two main types: a fused sentence, where independent clauses are pushed together with no punctuation at all, and a comma splice, where independent clauses are joined only by a comma. Both are errors because a comma alone cannot separate independent clauses.
Fused sentence: "I love physics it is my favourite subject." — no punctuation or connector between the two independent clauses.
Comma splice: "I love physics, it is my favourite subject." — only a comma separates the two independent clauses, which is insufficient.
Why it matters: Without correct boundaries, the reader cannot tell where one idea ends and the next begins, creating ambiguity.
Run-on sentences can be corrected in five ways: use a period, use a semicolon, use a comma plus a coordinating conjunction, use a subordinating conjunction to make one clause dependent, or restructure the sentence entirely.
Period: "I love physics. It is my favourite subject."
Semicolon: "I love physics; it is my favourite subject."
Comma + coordinating conjunction: "I love physics, and it is my favourite subject."
Subordinating conjunction: "I love physics because it is my favourite subject."
Restructure: "Physics is my favourite subject, which I love."
Misplaced Modifiers
A misplaced modifier is a word, phrase, or clause that is placed too far from the noun or pronoun it is meant to modify, causing confusion or unintentional humour. In English, modifiers should generally appear directly next to the word they describe. When a modifier drifts away from its target, the sentence can become ambiguous or absurd.
Position matters: "The student almost solved every problem on the test." means the student came close to solving every problem but may not have solved any. "The student solved almost every problem on the test." means the student solved most of the problems.
Prepositional phrase ambiguity: "I saw the man with the telescope." — who has the telescope? The speaker or the man?
Adverb placement: "She only told her friend." vs. "She told only her friend." — the position of "only" changes the meaning entirely.
Dangling Modifiers
A dangling modifier is a modifier (usually a participial or infinitive phrase) at the beginning of a sentence that has no logical subject in the sentence to attach to. Unlike a misplaced modifier, which is simply too far from its target, a dangling modifier has no appropriate target at all — the noun it should describe is entirely absent from the sentence.
Participial phrase with no subject: "Walking through the park, the flowers smelled wonderful." — the sentence implies the flowers were walking.
Infinitive phrase with no subject: "To win the tournament, practice is necessary." — practice cannot win the tournament; a player can.
Key test: Read the introductory modifier and then check the subject of the main clause. If the subject does not logically perform the action in the modifier, the modifier is dangling.
Parallel Structure (Parallelism)
Parallel structure (also called parallelism) means using the same grammatical form for elements that have the same function in a sentence. When items are in a list, a comparison, or a paired construction (such as both...and, either...or, not only...but also), each element must follow the same pattern — all nouns, all gerunds, all infinitives, or all clauses. Breaking this pattern creates a parallelism error.
Lists: "She likes hiking, swimming, and to ride bikes." → faulty. Correct: "She likes hiking, swimming, and riding bikes." (all gerunds).
Paired conjunctions: "He is both intelligent and works hard." → faulty. Correct: "He is both intelligent and hardworking." (both adjectives).
Comparisons: "The new model is faster than the old one and has more memory." → correct parallelism: two verb phrases. "The new model is faster and has more memory than the old one." → also correct.
Headings and outlines: Each item at the same level of an outline should use the same grammatical form.
Common Parallelism Markers
•
and → joins two items of the same form
•
or / nor → alternatives of the same form
•
both ... and → paired items of the same form
•
either ... or → paired alternatives of the same form
•
neither ... nor → paired negatives of the same form
•
not only ... but also → paired emphasis of the same form
•
whether ... or → paired alternatives of the same form
Parallelism applies beyond simple lists — it governs comparisons, headings, and any series of grammatically equivalent elements. Recognising the pattern a sentence establishes and then checking that every element follows it is the core skill.
Verb phrases in series: "She wants to study engineering, to design bridges, and building cities." → correct parallel: "to study engineering, to design bridges, and to build cities."
Noun phrases: "The course covers cell biology, genetics, and how organisms evolve." → correct parallel: "cell biology, genetics, and evolution."
Adjective series: "The solution was quick, efficient, and it was accurate." → correct parallel: "quick, efficient, and accurate."
Diagnostic Checklist for Faulty Sentence Structure
When editing any sentence for structural correctness, work through this checklist in order. Each check targets one of the six fault types covered above.
Step 1 — Find the main clause: Identify the subject and verb. If neither exists, the sentence is a sentence fragment.
Step 2 — Count independent clauses: If two or more independent clauses appear, check the punctuation and connector between them. A missing separator means a run-on sentence; a lone comma means a comma splice.
Step 3 — Locate modifiers: For each modifier, find the noun it describes. If the nearest noun is the wrong one, the modifier is misplaced. If no logical noun exists, it is dangling.
Step 4 — Check parallel forms: In every list, comparison, or paired construction, confirm that all elements share the same grammatical form. If not, there is a parallelism error.
Application Strategy
Worked Examples
Problem Statement
Identify the error in the following sentence and provide a corrected version: "Because the experiment was conducted at low temperature. The results were unusual."
sentence fragment
Step 1
Identify the fragment
Read the first group of words: it begins with the subordinating conjunction "Because" and contains a subject ("the experiment") and verb ("was conducted"), but it is a dependent clause that cannot stand alone as a sentence.
Step 2
Confirm the second clause is independent
The second group of words — "The results were unusual." — is an independent clause with a subject ("The results") and verb ("were unusual"). It can stand alone.
Step 3
Fix by attaching
Join the dependent clause to the independent clause with a comma. The dependent clause can come first (followed by a comma) or second (preceded by no comma).
"Because the experiment was conducted at low temperature, the results were unusual."
Problem Statement
Correct the comma splice: "The reaction was exothermic, it released a large amount of heat."
comma splicerun-on sentence
Step 1
Identify both independent clauses
Clause 1: "The reaction was exothermic." Clause 2: "It released a large amount of heat." Both are independent — each has a subject and a verb and expresses a complete thought.
Step 2
Recognise the comma splice
A comma alone separates the two independent clauses, which is insufficient. This is a comma splice.
Step 3
Apply a correction
Replace the comma with a semicolon, or add a coordinating conjunction after the comma, or use a period.
"The reaction was exothermic; it released a large amount of heat."
Problem Statement
Identify and correct the misplaced modifier: "The student almost answered every question correctly."
misplaced modifier
Step 1
Identify the modifier
The adverb "almost" modifies the verb "answered," but its current position before "answered" changes the meaning to suggest the student nearly answered every question but possibly answered none.
Step 2
Determine the intended meaning
The intended meaning is that the student answered most questions correctly, not that she came close to answering them all.
Step 3
Move the modifier next to its target
Place "almost" directly before "every" so it limits the quantity of questions rather than the act of answering.
"The student answered almost every question correctly."
Problem Statement
Identify and correct the dangling modifier: "After studying for hours, the test seemed easy."
dangling modifier
Step 1
Identify the modifier
The introductory participial phrase "After studying for hours" implies a person who studied. Look at the main clause subject to see who that person is.
Step 2
Check the main clause subject
The main clause subject is "the test." A test cannot study. The modifier has no logical subject to attach to — it is dangling.
Step 3
Supply the correct subject
Rewrite the main clause so its subject is the person who studied, or rewrite the modifier as a full subordinate clause.
"After studying for hours, I found the test easy."
Problem Statement
Identify and correct the parallelism error: "The scientist was respected for her dedication, intelligence, and how she communicated clearly."
parallel structureparallelism error
Step 1
Identify the list items
The list contains three items: (1) "dedication" (noun), (2) "intelligence" (noun), (3) "how she communicated clearly" (a clause). The first two are nouns; the third is a full clause — the forms do not match.
Step 2
Determine the required form
Since the first two items are nouns, the third item should also be a noun.
Step 3
Rewrite for parallelism
Convert the clause "how she communicated clearly" into a noun: "her clear communication."
"The scientist was respected for her dedication, intelligence, and clear communication."
Problem Statement
Correct the parallelism error: "The new drug is not only effective but also it is affordable."
parallel structureparallelism error
Step 1
Identify the correlative conjunction pair
The sentence uses "not only ... but also," which requires parallel forms on both sides.
Step 2
Check the forms after each conjunction
After "not only" we have the adjective "effective." After "but also" we have the clause "it is affordable." These forms are mismatched.
Step 3
Match both sides
Make both sides adjectives. Replace "it is affordable" with the adjective "affordable."
"The new drug is not only effective but also affordable."
Memorize formulas
No formulas for this topic.
Review
1
Which of the following is a sentence fragment?
Ans
Because the laboratory results were inconclusive.
Review
Tap to reveal
Identify the clause structure
Check whether each option contains at least one independent clause (a subject + verb expressing a complete thought).
Option A is only a subordinate clause introduced by 'because' — it is a fragment.
Verify the other options
Options B, C, and D each contain at least one independent clause with a subject ('results' or 'team') and a finite verb ('were', 'published').
Only Option A fails to express a complete thought.
2
Which revision correctly fixes the fragment: $"Walking through the botanical garden. The flowers were in full bloom."$
Ans
Walking through the botanical garden, I saw that the flowers were in full bloom.
Review
Tap to reveal
Diagnose the fragment
'Walking through the botanical garden' is a participial phrase, not an independent clause. It has no subject-verb pair.
The period separates a fragment from the main clause.
Attach the phrase to a complete clause
Replace the period with a comma and supply a subject and verb for the participial phrase to modify.
'Walking through the botanical garden, I saw that the flowers were in full bloom.'
3
Which of the following sentences is a run-on (fused sentence)?
Ans
The experiment concluded the researchers compiled their data.
Review
Tap to reveal
Identify independent clauses
Look for two or more independent clauses joined without proper punctuation or conjunctions.
Option B has two independent clauses ('The experiment concluded' + 'the researchers compiled their data') with no punctuation or conjunction — a fused sentence.
4
Which revision correctly fixes the run-on sentence: $"The data was collected it was then analysed using statistical methods."$
Ans
The data was collected; it was then analysed using statistical methods.
Review
Tap to reveal
Identify the two independent clauses
Clause 1: 'The data was collected.' Clause 2: 'It was then analysed using statistical methods.'
Two independent clauses with no punctuation between them.
Choose a correct separator
Options: period, semicolon, or comma + coordinating conjunction.
A semicolon is the cleanest fix, giving Option C.
5
Which sentence contains a comma splice?
Ans
The hypothesis was supported, the data showed a clear trend.
Review
Tap to reveal
Check each option for comma splice
A comma splice = two independent clauses separated by only a comma.
Option A joins 'The hypothesis was supported' and 'the data showed a clear trend' with only a comma — a comma splice.
6
Which revision correctly fixes the comma splice: $"The reaction was exothermic, the temperature of the solution rose steadily."$
Ans
The reaction was exothermic, so the temperature of the solution rose steadily.
Review
Tap to reveal
Identify the error
Two independent clauses joined by only a comma = comma splice.
'The reaction was exothermic' (independent) + 'the temperature of the solution rose steadily' (independent).
Apply the correct fix
Add a coordinating conjunction (for, and, nor, but, or, yet, so) after the comma.
'The reaction was exothermic, so the temperature of the solution rose steadily.'
7
Which sentence contains a misplaced modifier?
Ans
The student answered every question correctly who sat in the front row.
Review
Tap to reveal
Locate each modifier and its intended target
Check whether each modifying phrase or clause is next to the word it describes.
In Option B, 'who sat in the front row' modifies 'student' but is separated from it by the entire predicate.
8
Which revision correctly fixes the misplaced modifier: $"The researcher almost tested every sample in the batch."$
Ans
The researcher tested almost every sample in the batch.
Review
Tap to reveal
Identify the ambiguity
'Almost tested every sample' could mean 'nearly performed the testing' rather than 'tested most of the samples.'
The adverb 'almost' is misplaced relative to what it should modify ('every').
Reposition the modifier
Place 'almost' immediately before 'every' so it clearly modifies the quantity.
'The researcher tested almost every sample in the batch.'
9
Which sentence contains a dangling modifier?
Ans
Running late for class, the bus was missed by the student.
Review
Tap to reveal
Match the modifier to the subject
A sentence-initial participial phrase modifies the subject of the main clause. Check if that subject makes sense.
'Running late for class' must describe a person, but the subject of Option A's main clause is 'the bus' — a dangling modifier.
10
Which revision correctly fixes the dangling modifier: $"Having completed the experiment, the results were published immediately."$
Ans
Having completed the experiment, the researchers published the results immediately.
Review
Tap to reveal
Identify the dangling modifier
'Having completed the experiment' should modify a person, but the main clause subject is 'the results.'
The modifier dangles because results cannot complete experiments.
Supply the correct subject
Change the main clause subject to the agent who actually completed the experiment.
'Having completed the experiment, the researchers published the results immediately.'
11
Which sentence contains a parallelism error?
Ans
The procedure requires that we measure, mix, and heating the reagents.
Review
Tap to reveal
Check each series for grammatical consistency
Items in a list or series must all be the same part of speech or verb form.
Option B mixes base-form verbs ('measure,' 'mix') with a gerund ('heating') — a parallelism error.
12
Which revision correctly fixes the parallelism error: $"The new textbook is well-organised, clearly written, and it has detailed illustrations."$
Ans
The new textbook is well-organised, clearly written, and detailed in its illustrations.
Review
Tap to reveal
Identify the broken pattern
The series mixes two predicate adjectives ('well-organised,' 'clearly written') with an independent clause ('it has detailed illustrations').
The third item breaks the parallel adjective-phrase structure.
Restore parallelism
Convert the third item to match the adjective-phrase pattern of the first two.
'detailed in its illustrations' is an adjective phrase parallel to the first two items.
13
What type of error is present in the following sentence: $"The scientist presented her findings however the audience remained sceptical."$
Ans
Fused sentence (run-on)
Review
Tap to reveal
Identify the clause boundaries
'The scientist presented her findings' is an independent clause. 'the audience remained sceptical' is also an independent clause.
Two independent clauses with no punctuation or coordinating conjunction between them.
Classify the error
When two independent clauses are joined with no punctuation at all, the error is a fused sentence (a type of run-on).
This is a fused sentence.
14
Which sentence is grammatically correct with no structural errors?
Ans
To succeed in research, a scientist needs patience, dedication, and a methodical approach.
Review
Tap to reveal
Check each option for structural errors
Evaluate for fragments, run-ons, misplaced/dangling modifiers, and parallelism.
Option A: parallelism error. Option B: sentence fragment. Option C: no errors. Option D: dangling modifier.
Confirm Option C
'To succeed in research' modifies 'a scientist' (logical). The list 'patience, dedication, and a methodical approach' uses parallel noun phrases.
Option C is error-free.
15
Read the following sentence: $"The professor told the student that he should review the material carefully before the assessment."$ The pronoun 'he' in this sentence is an example of what potential structural issue?
Ans
Ambiguous pronoun reference — it is unclear whether 'he' refers to the professor or the student
Review
Tap to reveal
Identify possible antecedents for 'he'
Both 'the professor' and 'the student' are male nouns that could be the antecedent of 'he.'
The pronoun 'he' could refer to either person, creating ambiguity.
Classify the issue
When a pronoun could refer to more than one antecedent, it is called ambiguous pronoun reference.
This is ambiguous pronoun reference.
Question 1 of 15
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1
Which of the following is a sentence fragment?