English Grammar & Syntax Quiz: Identifying Run Ons And Comma Splices
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Identifying Run Ons And Comma SplicesQuestion 1 of 10

Which analysis best describes the following sentence?

Although the committee reviewed the budget twice, several figures remained provisional, the chair postponed the vote until Friday.

It is a comma splice because two independent clauses are joined only by the comma after "provisional."
It is a fused sentence because the two main clauses lack an intervening coordinating conjunction.
It is a correct complex-compound sentence because "although" subordinates everything before the final comma.
It is a sentence fragment because the opening subordinate clause cannot function as a complete sentence.
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English Grammar & Syntax Quiz

English Grammar & Syntax Quiz: Identifying Run Ons And Comma Splices

Practice Identifying Run Ons And Comma Splices in English Grammar & Syntax with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Identifying Run Ons And Comma Splices, giving you a quick way to practice the rules, question types, and explanations that matter most for English Grammar & Syntax.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Which analysis best describes the following sentence?

Although the committee reviewed the budget twice, several figures remained provisional, the chair postponed the vote until Friday.

  1. It is a comma splice because two independent clauses are joined only by the comma after "provisional." (correct answer)
  2. It is a fused sentence because the two main clauses lack an intervening coordinating conjunction.
  3. It is a correct complex-compound sentence because "although" subordinates everything before the final comma.
  4. It is a sentence fragment because the opening subordinate clause cannot function as a complete sentence.
Explanation: When analyzing a sentence for structural errors, your first job is to identify every clause and ask: how are these clauses connected? Count the finite verbs and their subjects, then check whether punctuation and conjunctions are doing their proper joining work. This sentence contains three clauses: "Although the committee reviewed the budget twice" (subordinate), "several figures remained provisional" (independent), and "the chair postponed the vote until Friday" (independent). The subordinating conjunction "although" attaches the first clause to the second, creating one complete complex unit. That leaves two independent clauses — "several figures remained provisional" and "the chair postponed the vote until Friday" — connected by nothing but a comma. Joining two independent clauses with only a comma is the textbook definition of a comma splice, making A the correct analysis. B is tempting but inaccurate. A fused sentence has no punctuation or conjunction between independent clauses. Here, a comma does appear — the problem is that a comma alone is insufficient, not absent. C is wrong because "although" only subordinates the opening clause to the first independent clause; it cannot reach across the comma and absorb the third clause as well. D misidentifies the error entirely — a fragment involves a clause that lacks a subject or verb or depends on a missing main clause. Every clause here is structurally complete; the problem is over-connection, not incompletion. As a study tip, always count independent clauses before labeling an error. Comma splice = two independents joined by comma only; fused = two independents with nothing between them. Don't confuse them — exams frequently use both as distractors for each other.

Question 2

(1) The first sensor, which had been stored in a sealed case, responded normally. (2) The second produced erratic readings the technician recalibrated it twice. (3) The readings improved, however, they remained too unstable for the trial. (4) After the supervisor arrived, the team documented the problem; then it postponed the trial.

Which statement correctly classifies sentences 2 and 3 in the passage?

  1. Sentence 2 is a comma splice, and sentence 3 is a fused sentence.
  2. Sentence 2 is a fused sentence, and sentence 3 is a comma splice. (correct answer)
  3. Both sentences are fused because neither uses a coordinating conjunction between its clauses.
  4. Both sentences are comma splices because each contains independent clauses without a conjunction.
Explanation: When a question asks you to classify sentence errors, your first job is to identify exactly how each sentence's independent clauses are joined — or rather, how they fail to be joined properly. Two common errors look similar but aren't: a fused sentence runs two independent clauses together with no punctuation at all, while a comma splice joins them with only a comma (which isn't strong enough to connect independent clauses). Look at sentence 2: "The second produced erratic readings the technician recalibrated it twice." There is no punctuation whatsoever between "readings" and "the technician" — two complete thoughts crammed together with nothing separating them. That's a fused sentence. Now look at sentence 3: "The readings improved, however, they remained too unstable for the trial." Here a comma appears before "however," but "however" is a conjunctive adverb, not a coordinating conjunction — it cannot join independent clauses with only a comma. This makes sentence 3 a classic comma splice. That confirms B as the correct answer. Choice A gets the labels exactly backwards, swapping which sentence is fused and which is a comma splice — a straightforward reversal error. Choice C claims both are fused sentences, but sentence 3 clearly does contain a comma, so it cannot be fused; the presence of that comma is precisely what defines the splice. Choice D claims both are comma splices, but sentence 2 has no comma at all, disqualifying it from that category. A useful memory trick: think "fused = no punctuation" and "splice = comma only." When you spot a conjunctive adverb like however, therefore, or nevertheless, remember it needs a semicolon before it — a comma alone always creates a splice.

Question 3

Which sentence contains a fused sentence rather than a comma splice or a correctly formed sentence?

  1. What the witness omitted later became important, the jury requested another interview.
  2. The witness omitted one important detail the jury later requested another interview. (correct answer)
  3. Because the witness omitted an important detail, the jury requested another interview.
  4. The witness omitted an important detail, and the jury requested another interview.
Explanation: When tackling questions about sentence errors, your first job is to distinguish between three things: a fused sentence (two independent clauses with no punctuation or conjunction between them), a comma splice (two independent clauses joined only by a comma), and a correctly formed sentence (properly joined with a conjunction, semicolon, or subordinating word). Option B is the fused sentence. Read it carefully: "The witness omitted one important detail the jury later requested another interview." Two complete thoughts — "The witness omitted one important detail" and "the jury later requested another interview" — crash directly into each other with nothing separating them. No comma, no conjunction, no punctuation at all. That's the definition of a fused sentence, making B the correct answer. Option A is a comma splice, not a fused sentence. It has a comma between "important" and "the jury," but a comma alone cannot join two independent clauses — you need a coordinating conjunction alongside it or a stronger punctuation mark. Option C is correctly formed: the subordinating conjunction "because" turns the first clause into a dependent clause, which is then properly attached to the independent clause. Option D is also correct, using the coordinating conjunction "and" paired with a comma — the standard way to join two independent clauses. A quick strategy: when you see answer choices mixing sentence errors, test each one by finding the subject and verb of every clause, then check what — if anything — connects them. No connector at all = fused sentence. Comma only = comma splice. Conjunction or subordination = likely correct.

Question 4

When the fog lifted, the harbor lights became visible. The crew prepared to dock the pilot requested another depth reading. Although the tide was rising, the channel remained shallow, so the captain slowed the vessel. The reading was reassuring, nevertheless, the captain maintained a reduced speed.

How many fused sentences and comma splices appear in the passage?

  1. Two fused sentences and no comma splices appear in the passage.
  2. One fused sentence and one comma splice appear in the passage. (correct answer)
  3. No fused sentences and two comma splices appear in the passage.
  4. One fused sentence and no comma splices appear in the passage.
Explanation: When identifying sentence-boundary errors, you need to distinguish between two types: a fused sentence (two independent clauses joined with no punctuation or coordinating conjunction) and a comma splice (two independent clauses joined with only a comma). Scan each sentence boundary carefully before choosing. In this passage, two problem spots emerge. First, look at "The crew prepared to dock the pilot requested another depth reading." There is no punctuation or conjunction between "dock" and "the pilot" — two complete independent clauses collide with nothing between them. That is a fused sentence. Second, examine "The reading was reassuring, nevertheless, the captain maintained a reduced speed." Here, a comma connects two independent clauses. "Nevertheless" is a conjunctive adverb, not a coordinating conjunction, so a comma alone cannot link these clauses — a semicolon is required before "nevertheless." That makes this a comma splice. Together, one fused sentence and one comma splice appear, confirming that B is correct. Choice A is wrong because it claims two fused sentences with no comma splices, but the "nevertheless" error is clearly a comma splice, not a fused sentence. Choice C is wrong because it claims no fused sentences and two comma splices — it misidentifies the "dock / the pilot" boundary as a comma splice when it actually has no punctuation at all. Choice D is wrong because it acknowledges only the fused sentence while ignoring the comma splice entirely. A useful strategy: when you spot a conjunctive adverb like however, nevertheless, or therefore between two clauses, always check whether it is preceded by a semicolon. A comma before these words is almost always a comma splice.

Question 5

Begin with this correctly punctuated sentence:

The alarm sounded, and the guards closed the gate.

Edit 1 removes only the word "and." Edit 2 removes both the comma and the word "and." Which classification is accurate?

  1. Both edits create comma splices because both leave adjacent independent clauses.
  2. Edit 1 creates a fused sentence, whereas Edit 2 creates a comma splice.
  3. Both edits create fused sentences because both eliminate the coordinating conjunction.
  4. Edit 1 creates a comma splice, whereas Edit 2 creates a fused sentence. (correct answer)
Explanation: When a question asks you to classify sentence errors, your first job is to nail down the definitions: a comma splice joins two independent clauses with only a comma, while a fused sentence (also called a run-on) joins two independent clauses with no punctuation at all. Start with the original: The alarm sounded, and the guards closed the gate. This is correct because a coordinating conjunction ("and") plus a comma properly links two independent clauses. Edit 1 removes only "and," leaving: The alarm sounded, the guards closed the gate. The comma remains, but the conjunction is gone — two independent clauses separated by nothing but a comma. That's the textbook definition of a comma splice. Edit 2 removes both the comma and "and," leaving: The alarm sounded the guards closed the gate. Now there's no separator whatsoever between the two clauses — that's a fused sentence. Answer D correctly identifies this distinction. Here's why the wrong answers fail: A claims both edits produce comma splices, but Edit 2 has no comma at all, so it can't be a comma splice. B reverses the two errors — it labels Edit 1 a fused sentence and Edit 2 a comma splice, which is exactly backwards. C claims both edits produce fused sentences, ignoring that Edit 1 still retains the comma, which is precisely what makes it a splice rather than a fusion. A handy study tip: let the punctuation guide you. If a comma is still present but the conjunction is missing, think splice. If there's nothing between the clauses, think fused.

Question 6

Which analysis best describes the following sentence?

The editor called the ending 'too abrupt,' the author defended its suddenness.

  1. It is fused because punctuation inside a quotation cannot separate the surrounding independent clauses.
  2. It is correct because the comma required with the quotation also coordinates the two main clauses.
  3. It is a comma splice because the quotation-ending comma is the only link between two independent clauses. (correct answer)
  4. It is a fragment because the quoted words do not form an independent clause of their own.
Explanation: When a sentence contains a direct quotation, it's easy to let the quotation's punctuation distract you from the underlying sentence structure. The key move here is to mentally strip away the quotation and ask: what clauses remain, and how are they connected? Do that with this sentence and you get two independent clauses — "The editor called the ending [something]" and "the author defended its suddenness" — joined by nothing but a comma. That is the textbook definition of a comma splice, making C the correct answer. The comma that closes the quotation mark is doing quotation duty, not grammatical coordination duty. It cannot simultaneously serve as a clause-level connector. A is a trap that overcorrects. A fused sentence has no punctuation between independent clauses; this sentence does have a comma, so it isn't fused. The problem isn't absence of punctuation — it's that the punctuation present is insufficient for the job. B describes a comma that doesn't exist. No comma is "required" by the quotation that would coincidentally coordinate two main clauses. Quotation-closing commas serve a narrow typographical function; they don't grant coordinating power between clauses on either side of them. D misidentifies the problem entirely. A fragment is a clause missing a subject or verb, or a dependent clause standing alone. Both main clauses here are grammatically complete — the issue is how they relate to each other, not whether either is incomplete on its own. Your study tip: whenever quotation marks appear mid-sentence, look past them. Identify the independent clauses in the surrounding sentence and check whether they're properly joined by a coordinating conjunction, a semicolon, or a period.

Question 7

Consider the following sentence:

The shipment arrived after closing, therefore, no clerk inspected it until morning.

Which analysis identifies the error and the most direct one-mark correction?

  1. It is a comma splice; replace the comma after "closing" with a semicolon. (correct answer)
  2. It is a fused sentence; replace the comma after "therefore" with a semicolon.
  3. It is a comma splice; remove the comma after "closing" without adding other punctuation.
  4. It is correctly punctuated because "therefore" coordinates the two independent clauses.
Explanation: When you spot a conjunctive adverb like therefore, however, or consequently joining two independent clauses, your job is to check whether the punctuation on both sides of it is correct — this is a classic comma splice trap. Here, the sentence contains two independent clauses: "The shipment arrived after closing" and "no clerk inspected it until morning." The word therefore is a conjunctive adverb, not a coordinating conjunction, so it cannot join independent clauses with only a comma. The comma after "closing" creates a comma splice — two complete sentences glued together with just a comma. The standard fix is to upgrade that comma to a semicolon, giving you: The shipment arrived after closing*;** therefore, no clerk inspected it until morning.* The comma after therefore is actually correct, because conjunctive adverbs take a comma following them. That makes A the right answer. B is wrong on two counts: the sentence isn't a fused sentence (it does have punctuation between the clauses), and replacing the comma after therefore would remove the correctly placed comma, not fix the real problem. C correctly identifies the comma splice but proposes the wrong fix — removing the comma after "closing" without replacing it would create a fused sentence, which is worse. D is a fundamental misconception; therefore is a conjunctive adverb, not a coordinating conjunction like for, and, nor, but, or, yet, so (FANBOYS), and conjunctive adverbs cannot join independent clauses with a comma alone. Your study tip: memorize that conjunctive adverbs need a semicolon before and a comma after when joining two independent clauses — the pattern is ; therefore, not just , therefore,.

Question 8

Which sentence contains neither a fused sentence nor a comma splice?

  1. The road narrowed where the ridge began, yet the bus maintained its speed. (correct answer)
  2. The road narrowed at the ridge, nevertheless, the bus maintained its speed.
  3. The road narrowed at the ridge the driver immediately reduced the bus's speed.
  4. The road, which narrowed at the ridge, became slick, the driver reduced the speed.
Explanation: When a question asks you to identify a sentence free of fused sentences and comma splices, you need to understand how independent clauses can be correctly joined. Two independent clauses require either a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so), a semicolon, or a period — anything less creates an error. Choice A is the correct answer. It joins two independent clauses — "The road narrowed where the ridge began" and "the bus maintained its speed" — using a comma followed by the coordinating conjunction yet. This is a textbook correct compound sentence structure. Choice B looks close but contains a classic trap. Nevertheless is a conjunctive adverb, not a coordinating conjunction. When a conjunctive adverb connects two independent clauses, you need a semicolon before it, not a comma. Writing "the road narrowed at the ridge, nevertheless, the bus maintained its speed" is a comma splice. Choice C is a fused sentence (also called a run-on). There is no punctuation or conjunction between "the road narrowed at the ridge" and "the driver immediately reduced the bus's speed" — the two clauses simply crash into each other with nothing separating them. Choice D commits a comma splice at the second join. The clause "became slick" ends with a comma before "the driver reduced the speed," which are two independent clauses improperly joined by a comma alone. Your study tip: always test whether the word connecting two clauses is a true coordinating conjunction (FANBOYS) or a conjunctive adverb (however, nevertheless, therefore). Conjunctive adverbs demand a semicolon — a comma alone will always produce a splice.

Question 9

Which sentence avoids both a fused sentence and a comma splice?

  1. The proposal seemed practical, the accountant reviewed the projected costs more carefully.
  2. The proposal seemed practical the accountant had not yet reviewed the projected costs.
  3. The proposal seemed practical until the accountant reviewed the projected costs. (correct answer)
  4. The proposal seemed practical, therefore, the accountant reviewed the projected costs.
Explanation: When you see a question about fused sentences and comma splices, you're being tested on one core skill: recognizing when two independent clauses are joined incorrectly — and knowing how to fix it. A fused sentence occurs when two independent clauses are crammed together with no punctuation or conjunction at all. A comma splice occurs when they're joined with only a comma, which isn't strong enough to connect independent clauses on its own. Option C — "The proposal seemed practical until the accountant reviewed the projected costs" — is correct because the word until is a subordinating conjunction. It transforms the second clause into a dependent clause, meaning you no longer have two independent clauses competing for connection. The sentence becomes one complete, grammatically sound unit with no splice or fusion in sight. Option A is a classic comma splice: two independent clauses ("The proposal seemed practical" and "the accountant reviewed...") joined by only a comma. Option B is a fused sentence — those same two independent clauses are simply smashed together with no punctuation whatsoever. Option D is a trickier trap: therefore is a conjunctive adverb, not a coordinating conjunction. To use it correctly, you'd need a semicolon before it (; therefore,), not a comma. Using a comma before therefore still produces a comma splice. Your go-to strategy: when checking for these errors, identify whether each clause can stand alone as a sentence. If both can, you need more than a comma — try a semicolon, a coordinating conjunction (FANBOYS), or a subordinating conjunction to make one clause dependent.

Question 10

Which analysis best describes the following sentence?

After you verify the labels, place the carton on the loading dock, the courier will collect it at noon.

  1. It is fused because no punctuation separates the imperative clause from the declarative clause.
  2. It is correct because the opening subordinate clause governs both clauses that follow it.
  3. It is a comma splice because an imperative clause and a declarative clause are joined only by a comma. (correct answer)
  4. It is a fragment because the imperative clause lacks an explicitly stated grammatical subject.
Explanation: When analyzing sentence-level errors, your first step is always to identify how many independent clauses are present and what punctuation (if any) connects them. An independent clause can stand alone as a complete sentence — and crucially, imperative clauses ("place the carton on the loading dock") count as independent clauses even though their subject you is implied rather than written out. In this sentence, you have two independent clauses joined by only a comma: the imperative "place the carton on the loading dock" and the declarative "the courier will collect it at noon." Joining two independent clauses with nothing but a comma is the textbook definition of a comma splice, making C the correct answer. A correct revision might use a period, semicolon, or coordinating conjunction: place the carton on the loading dock; the courier will collect it at noon. A misidentifies the error as a fused sentence. A fused sentence has no punctuation between independent clauses — but there is a comma here, so the error type is a comma splice, not a fusion. B is the most tempting distractor: students often assume an opening subordinate clause ("After you verify the labels") can act as an umbrella that ties everything together. It cannot — the subordinate clause modifies only one independent clause, and it does nothing to legitimately join two independent clauses to each other. D is simply wrong because implied subjects in imperative clauses are grammatically acceptable; a missing stated subject does not make a clause a fragment. Your study tip: whenever you spot a comma between two clauses, ask yourself whether each side could stand alone as a sentence. If yes, a comma alone isn't enough — you have a comma splice.