SAT / PSAT: SAT PSAT Reading Writing - Standard English Conventions, Sentence Structure, Fragments and Run-ons

What Is This?

Sentence structure refers to the way words are arranged to form sentences. Fragments and run-ons are common errors in sentence structure. A fragment is an incomplete sentence that lacks a subject, a verb, or both. A run-on is a sentence that improperly joins two or more independent clauses without proper punctuation or a coordinating conjunction. This topic appears in exams to test your ability to identify and correct these errors, ensuring clear and effective communication.

Why It Matters

This topic is frequently tested in standardized exams like the SAT, ACT, and GRE, as well as in English proficiency tests like the TOEFL and IELTS. It typically carries moderate marks but is crucial for demonstrating your mastery of basic English grammar and sentence structure. This skill is essential for effective written communication in academic and professional settings.

Core Concepts

1. Independent Clause: A group of words that contains a subject and a verb and expresses a complete thought.
2. Fragment: An incomplete sentence that lacks a subject, a verb, or both.
3. Run-on Sentence: A sentence that improperly joins two or more independent clauses without proper punctuation or a coordinating conjunction.
4. Coordinating Conjunctions: Words like and, but, or, nor, for, yet, so that can join independent clauses.
5. Punctuation: Use of periods, commas, semicolons, and colons to separate independent clauses correctly.

Prerequisites

1. Basic Grammar: Understanding of subjects, verbs, and clauses.
2. Punctuation Rules: Knowledge of how to use periods, commas, semicolons, and colons.
3. Coordinating Conjunctions: Familiarity with words that can join independent clauses.

The Rule-Book (How It Works)

Primary Rule

• A complete sentence must have an independent clause with a subject and a verb.

Sub-rules, Exceptions, and Edge Cases

1. Fragments: Can be a phrase or a dependent clause that does not express a complete thought.
2. Example: Running quickly. (This is a fragment because it lacks a subject.)
3. Run-ons: Can be corrected by using a period, semicolon, or coordinating conjunction.
4. Example: I went to the store I bought some milk. (This is a run-on and can be corrected as: I went to the store, and I bought some milk.)
5. Semicolons: Can be used to join two closely related independent clauses.
6. Example: I went to the store; I bought some milk.

Visual Pattern

• Fragment: [Phrase or Dependent Clause]
• Run-on: [Independent Clause] [Independent Clause]
• Corrected Run-on: [Independent Clause], [Coordinating Conjunction] [Independent Clause].

Exam / Job / Audit Weighting

• Frequency: Moderate
• Difficulty Rating: Intermediate
• Question Type or Real-World Task Type: Identification and correction of sentence structure errors

Difficulty Level

Intermediate

Must-Know Rules, Formulas, Standards, or Principles

1. A complete sentence must have an independent clause with a subject and a verb.
2. A fragment is an incomplete sentence that lacks a subject, a verb, or both.
3. A run-on sentence improperly joins two or more independent clauses without proper punctuation or a coordinating conjunction.

Worked Examples (Step-by-Step)

Easy

Question: Identify and correct the fragment. Running quickly to catch the bus.

Step-by-Step:
1. Identify the fragment: Running quickly to catch the bus.
2. Add a subject and a verb to complete the thought: She was running quickly to catch the bus.

Answer: She was running quickly to catch the bus. Key Rule Applied: A complete sentence must have an independent clause with a subject and a verb.

Medium

Question: Identify and correct the run-on sentence. I went to the store I bought some milk.

Step-by-Step:
1. Identify the run-on: I went to the store I bought some milk.
2. Separate the independent clauses: I went to the store. I bought some milk.
3. Use a coordinating conjunction: I went to the store, and I bought some milk.

Answer: I went to the store, and I bought some milk. Key Rule Applied: A run-on sentence can be corrected by using a period, semicolon, or coordinating conjunction.

Hard

Question: Identify and correct the fragment and run-on in the following passage. Running quickly to catch the bus. I missed it I was late for work.

Step-by-Step:
1. Identify the fragment: Running quickly to catch the bus.
2. Correct the fragment: I was running quickly to catch the bus.
3. Identify the run-on: I missed it I was late for work.
4. Correct the run-on: I missed it, and I was late for work.

Answer: I was running quickly to catch the bus. I missed it, and I was late for work. Key Rule Applied: A complete sentence must have an independent clause with a subject and a verb; a run-on sentence can be corrected by using a period, semicolon, or coordinating conjunction.

Common Exam Traps & Mistakes

1. Mistake: Treating a dependent clause as a complete sentence.
2. Wrong Answer: Because I was tired.

3. Correct Approach: Add an independent clause: Because I was tired, I went to bed early.

4. Mistake: Using a comma splice to join independent clauses.

5. Wrong Answer: I went to the store, I bought some milk.

6. Correct Approach: Use a period or a coordinating conjunction: I went to the store. I bought some milk. or I went to the store, and I bought some milk.

7. Mistake: Treating a phrase as a complete sentence.

8. Wrong Answer: In the morning.

9. Correct Approach: Add a subject and a verb: I wake up in the morning.

10. Mistake: Using a semicolon incorrectly.

11. Wrong Answer: I went to the store; and I bought some milk.
12. Correct Approach: Use a semicolon without "and": I went to the store; I bought some milk.

Shortcut Strategies & Exam Hacks

1. Memory Aid: Remember "S + V = Complete Sentence" for fragments.
2. Elimination Strategy: If a sentence lacks a subject or a verb, it's a fragment.
3. Pattern Recognition: Look for independent clauses joined without proper punctuation for run-ons.
4. Formula Shortcut: Use "Period, Semicolon, or Conjunction" to correct run-ons.

Question-Type Taxonomy

1. Identification: Identify the fragment or run-on in a sentence.
2. Example: Which of the following is a fragment?

3. Favored By: SAT, ACT

4. Correction: Correct the fragment or run-on.

5. Example: Correct the run-on sentence: I went to the store I bought some milk.

6. Favored By: GRE, TOEFL

7. Multiple Choice: Choose the correct version of a sentence from multiple options.

8. Example: Which of the following is a complete sentence?
9. Favored By: IELTS, ACT

Practice Set (MCQs)

Question 1

Question: Which of the following is a fragment? A. Running quickly to catch the bus. B. I went to the store. C. She bought some milk. D. Because I was tired.

Correct Answer: A. Running quickly to catch the bus. Explanation: A fragment lacks a subject, a verb, or both. "Running quickly to catch the bus" lacks a subject. Why the Distractors Are Tempting: B and C are complete sentences. D is a dependent clause but can be part of a complete sentence.

Question 2

Question: Correct the run-on sentence: I went to the store I bought some milk. A. I went to the store, and I bought some milk. B. I went to the store; I bought some milk. C. I went to the store I bought some milk. D. I went to the store. I bought some milk.

Correct Answer: A. I went to the store, and I bought some milk. Explanation: A run-on sentence can be corrected by using a coordinating conjunction. Why the Distractors Are Tempting: B and D are correct but less common. C is the original run-on.

Question 3

Question: Which of the following is a complete sentence? A. In the morning. B. Because I was tired. C. She went to bed early. D. Running quickly.

Correct Answer: C. She went to bed early. Explanation: A complete sentence has an independent clause with a subject and a verb. Why the Distractors Are Tempting: A and D are phrases. B is a dependent clause.

Question 4

Question: Correct the fragment: Running quickly to catch the bus. A. Running quickly to catch the bus. B. She was running quickly to catch the bus. C. To catch the bus. D. Quickly to catch the bus.

Correct Answer: B. She was running quickly to catch the bus. Explanation: A fragment can be corrected by adding a subject and a verb. Why the Distractors Are Tempting: A, C, and D are incomplete sentences.

Question 5

Question: Identify the run-on sentence: A. I went to the store, and I bought some milk. B. I went to the store I bought some milk. C. I went to the store; I bought some milk. D. I went to the store. I bought some milk.

Correct Answer: B. I went to the store I bought some milk. Explanation: A run-on sentence improperly joins two independent clauses without proper punctuation or a coordinating conjunction. Why the Distractors Are Tempting: A, C, and D are correctly punctuated sentences.

30-Second Cheat Sheet

• A complete sentence must have an independent clause with a subject and a verb.
• A fragment is an incomplete sentence that lacks a subject, a verb, or both.
• A run-on sentence improperly joins two or more independent clauses without proper punctuation or a coordinating conjunction.
• Use periods, semicolons, or coordinating conjunctions to correct run-ons.
• Remember "S + V = Complete Sentence" for fragments.
• Look for independent clauses joined without proper punctuation for run-ons.
• Use "Period, Semicolon, or Conjunction" to correct run-ons.

Learning Path

1. Beginner Foundation: Review basic grammar rules for subjects, verbs, and clauses.
2. Core Rules: Learn the definitions and corrections for fragments and run-ons.
3. Practice: Work through examples and practice identifying and correcting fragments and run-ons.
4. Timed Drills: Practice under time constraints to improve speed and accuracy.
5. Mock Tests: Take full-length practice tests to simulate exam conditions.

Related Topics

1. Subject-Verb Agreement: Ensures that the subject and verb agree in number.
2. Punctuation Rules: Covers the use of periods, commas, semicolons, and colons.
3. Coordinating Conjunctions: Explains the use of words like and, but, or, nor, for, yet, so to join independent clauses.