How do you fix comma splices, run-ons, and fragments, and how do you combine short sentences into clearer, more varied ones?
Sentence boundaries and combining: recognizing and correcting comma splices, run-on sentences, and fragments, and combining short or choppy sentences into clearer, more varied ones using coordination, subordination, and appositives, on a LEAP English I or II revising and editing item.
How to handle sentence boundaries on a LEAP English I or II item: fixing comma splices, run-ons, and fragments, and combining choppy sentences using coordination, subordination, and appositives for clearer, more varied writing. These boundary skills are tested in editing items and rewarded on the writing rubrics.
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What this skill is asking
Sentence boundaries and combining cover two related editing tasks: fixing the errors that come from joining sentences wrongly, comma splices, run-ons, and fragments, and combining short, choppy sentences into clearer, more varied ones. LEAP English I and II test both in the revising and editing items, and both matter for the writing rubrics, where controlled, varied sentences read better and avoid boundary errors. The boundary errors are among the most common on the test, and combining is a revision skill that lifts the quality of writing. This page covers recognizing and correcting the three boundary errors and the main ways to combine sentences (coordination, subordination, and appositives or modifiers). The transferable skill is controlling where sentences begin and end and shaping them for clarity, which keeps your own writing both correct and fluent.
Fixing the three boundary errors
Boundary errors all come from mishandling independent clauses.
Subordination is often the cleanest fix because it also shows the relationship between the ideas: "When the bell rang, the students left" both joins the clauses and signals cause or sequence. Recognizing whether a sentence is a splice, a run-on, or a fragment tells you which fix applies. These errors are the same ones introduced in the punctuation and sentence-structure page; here the task is to correct them in a draft. They are high-frequency on the editing items and high-cost on the writing rubrics, where a string of boundary errors hurts the conventions score.
Combining for clarity and variety
The second task turns choppy writing into smooth prose.
Combining is a revision skill, not just an error fix: it makes writing more sophisticated and is part of the sentence variety that strong writing shows. It connects to revising for clarity (better-structured sentences) and to word choice and precision (tighter wording), and it directly serves the writing dimensions, where varied, controlled sentences read better than choppy or run-on ones. Controlling sentence boundaries and combining sentences well is a mark of a writer in command of their prose.
Working a boundary or combining item
Try this
Q1. What are the four standard ways to fix a comma splice or run-on? [Recall]
- Cue. A period (two sentences), a semicolon, a comma plus a coordinating conjunction (and, but, so), or subordination (making one clause dependent with "when," "because"). Subordination also shows the relationship between the ideas.
Q2. Combine these for clarity: "The storm was severe. It knocked out power. It lasted three hours." [Short explanation]
- Cue. One clear combination is "The severe storm knocked out power for three hours," which folds the details into a single varied sentence using a modifier ("severe") and a phrase ("for three hours") without losing information or creating a boundary error.
Exam-style practice questions
Practice questions written in the style of LDOE exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
LEAP 2025 English I (style)1 marksFix the boundary error: 'The bell rang the students rushed out.' Which correction is best? (1) 'The bell rang the students rushed out.' (2) 'The bell rang, the students rushed out.' (3) 'When the bell rang, the students rushed out.' (4) 'The bell rang students rushed out.'Show worked answer →
Answer: (3). The original is a run-on: two independent clauses with no punctuation. "When the bell rang, the students rushed out" fixes it by making the first clause dependent (subordination), which joins the ideas correctly and shows their relationship.
Why not the others: (1) keeps the run-on; (2) is a comma splice (a comma alone cannot join two independent clauses); (4) deletes words and still runs the clauses together. A semicolon or a comma-plus-conjunction would also work, but subordination is the cleanest of the offered fixes.
LEAP 2025 English II (style)1 marksCombine for clarity and variety: 'The museum is free. It is open on weekends. It is downtown.' Which is the best combination? (1) 'The museum is free it is open on weekends it is downtown.' (2) 'The free downtown museum is open on weekends.' (3) 'The museum is free, it is open on weekends, it is downtown.' (4) 'The museum, free, weekends, downtown.'Show worked answer →
Answer: (2). Combining the three short sentences into "The free downtown museum is open on weekends" folds the details into one clear, varied sentence, turning choppy writing into smooth prose without losing information.
Why not the others: (1) is a run-on; (3) is a string of comma splices; (4) is a fragment with no verb. Sentence combining uses coordination, subordination, and modifiers (here, the adjectives "free" and "downtown") to merge short sentences into clearer, more sophisticated ones.
Related dot points
- Revising for clarity and organization: improving a draft's focus, development, and organization by choosing the best transition, the most logical sentence order, the sentence that best supports a point, or the change that sharpens meaning, distinguishing revising (content and clarity) from editing (mechanics) on a LEAP English I or II revising and editing item.
How to revise a draft on a LEAP English I or II revising and editing item: improving focus, development, and organization by choosing the best transition, sentence order, or supporting sentence. Revising targets clarity and content; editing targets mechanics, and these items reward the change that improves meaning.
- Editing for grammar and usage: identifying and correcting errors in subject-verb agreement, pronoun-antecedent agreement and reference, verb tense, and modifier placement within a draft passage, choosing the correction that follows standard English, on a LEAP English I or II revising and editing item.
How to edit for grammar and usage on a LEAP English I or II item: spotting and fixing subject-verb agreement, pronoun agreement and reference, tense, and modifier errors in a draft, and choosing the correction that follows standard English. The same conventions are scored on the writing rubrics.
- Word choice and precision: improving a draft by choosing the most precise and appropriate word, cutting wordiness and redundancy, matching tone and register to the writing, and selecting words for their connotation, on a LEAP English I or II revising and editing item, the skill that also lifts written expression on the prose responses.
How to improve word choice on a LEAP English I or II item: choosing the most precise, appropriate word, cutting wordiness and redundancy, and matching tone and connotation. Precise word choice is tested in editing items and rewarded in the written-expression and conventions dimensions of the writing rubrics.
- Punctuation and sentence structure: applying the conventions of capitalization, punctuation (commas, semicolons, colons, apostrophes, and end marks), and correct sentence boundaries, recognizing and fixing comma splices, run-on sentences, and fragments, as tested in editing items and rewarded in the Knowledge of Language and Conventions dimension of the LEAP writing rubrics.
The punctuation and sentence-structure conventions LEAP English I and II expect: commas, semicolons, colons, apostrophes, and correct sentence boundaries, including fixing comma splices, run-ons, and fragments. Tested in editing items and scored in the conventions dimension of the writing rubrics.
- The LEAP writing rubric and scoring: how the two prose constructed-response rubrics work, the analytic rubric for the Literary Analysis and Research Simulation tasks (Reading Comprehension and Written Expression, holistic 0 to 4 times 4, plus Knowledge of Language and Conventions 0 to 3, up to 19) and the narrative rubric for the Narrative Writing Task (Written Expression 0 to 4 times 3, plus conventions 0 to 3, up to 15), the rule that an unscorable response earns 0, and how to write toward the top of each, for LEAP English I and II.
How the LEAP English I and II prose responses are scored: the analytic rubric (Reading Comprehension and Written Expression 0 to 4 times 4, plus conventions 0 to 3, up to 19) for the Literary Analysis and Research Simulation tasks, and the narrative rubric (Written Expression 0 to 4 times 3, plus conventions, up to 15). What each dimension rewards and how to write toward the top.
Sources & how we know this
- LEAP 2025 Assessment Guide for English I and English II — LDOE (2025)
- Louisiana Student Standards for English Language Arts — LDOE (2025)