Complete Grammar Explanation & Interactive Answer Key
Identifying and Revising Sentences and Sentence Fragments • Understood Subjects • Interactive Study Guide
What Is a Sentence vs. a Sentence Fragment? (Rule 2a)
A sentence is a word group that contains both a subject and a verb and that expresses a complete thought. By contrast, a sentence fragment is a word group capitalized and punctuated as a sentence that is missing a subject, missing a verb, or fails to express a complete thought:
| Word Group Classification | Why It Is Complete or Incomplete | Textbook Fragment vs. Revised Sentence |
|---|---|---|
| Complete Sentence | Has a subject, has a verb, and makes complete sense by itself. | In many ways, the development of the microprocessor has revolutionized technology. |
| Fragment Type 1: Missing Subject | Contains a verb phrase, but does not state who or what performs the action. | Fragment: Sponsors election-year debates. Sentence: The League of Women Voters sponsors election-year debates. |
| Fragment Type 2: Missing Verb | Names a noun/subject with modifiers or participles (-ing/-ed), but lacks a main verb. | Fragment: Students representing sixty-one historically black universities and colleges. Sentence: Students representing sixty-one historically black universities and colleges competed. |
| Fragment Type 3: Dependent Clause | Contains a subject and a verb, but starts with a subordinating conjunction (because, when). | Fragment: Because the graduation ceremony was rescheduled for June 20. Sentence: Because the graduation ceremony was rescheduled for June 20, my cousin Larry could attend after all. |
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Important Notice for Students, Parents, and Educators: This grammar guide and interactive answer key is published strictly for educational help, academic support, self-checking, and concept mastery—NOT for cheating or copying homework. Study the rules on sentences and sentence fragments below, decide whether each item in Exercise 1 is a sentence or a fragment and write your own revision first, and then click Click to Show Answer to check your work.
Complete Lesson Explanation: The Sentence (Rule 2a)
Rule 2a: A sentence is a word group that contains a subject and a verb and that expresses a complete thought.
A thought is complete when it makes sense by itself. Every sentence should begin with a capital letter, and the punctuation mark that follows a sentence (period ., question mark ?, or exclamation point !) depends on the purpose of the sentence:
- Declarative (Statement): In many ways, the development of the microprocessor has revolutionized technology.
- Interrogative (Question): When did Mexico achieve independence from Spain?
- Exclamatory (Exclamation): How quickly this year has passed!
- Imperative (Command/Request): Stop! (The understood subject is you.)
1. How to Spot and Fix Sentence Fragments
Do not mistake a sentence fragment for a sentence. A sentence fragment is a group of words that is capitalized and punctuated as a sentence but that does not contain both a subject and a verb or does not express a complete thought. Use this 3-step test on every word group in Exercise 1:
| Diagnostic Question | What to Look For | How to Fix It If It Fails |
|---|---|---|
| 1. Does it have a finite main verb? | Watch out for -ing participles (stretching), past participles (held, anticipated), or to + verb infinitives (to estimate) standing alone without a main verb! (Note: An -ing gerund phrase CAN act as the subject of a real verb, as in Item 9: "Covering the portrait's face... was the bold act...") | Add a subject and a main verb, or attach the phrase to an independent clause (Items 2, 4, 6, and 7). |
| 2. Does it have a subject? | Ask "Who or what performs the verb?" Remember two special cases that ARE complete sentences: • Imperative sentences have the understood subject (you) (Item 8: "Take this as an example."). • Inverted sentences place the subject after the verb (Item 1: "Here in the basement... lay [verb] stacks and stacks [subject]..."). |
Supply a clear subject for the verb. |
| 3. Does it express a complete thought? | Even if a word group has a subject and a verb, if it begins with a subordinating conjunction (such as when, because, after, although, if), it is a dependent clause and cannot stand alone (e.g., "When the judges announced the winner" or Item 5: "when they swam under the boat..."). | Method A: Add an independent clause ("When the judges announced the winner, everyone applauded.") Method B: Delete the subordinating conjunction ("The judges announced the winner.") |
Exercise 1: Identifying and Revising Sentences and Sentence Fragments (Items 1–10)
Directions: Decide which of the following word groups are sentences and which are sentence fragments. If a word group is a sentence, add appropriate capitalization and punctuation. If a word group is a sentence fragment, revise the fragment by adding or deleting words to make it a sentence. Then, add appropriate capitalization and punctuation. (Note: Revised sentences for fragments 2, 4, 5, 6, and 7 will vary; below are the verified Teacher's Edition solutions.)
Answer: Sentence Fragment American Indians, such as the Sioux, Cheyenne, and Comanche, were expert equestrians.
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- Correctly Punctuated Sentence: Here in the basement of the library lay stacks and stacks of dusty magazines, each a collector's prize.
- Why It Is a Sentence: This is an inverted declarative sentence. The verb is lay, and the compound subject following the verb is stacks and stacks. It expresses a complete thought and only needs a capital H and a closing period.
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- Revised Sentence: Stretching in a seemingly endless blue expanse from the coast of Peru to the Great Barrier Reef, the Pacific Ocean is immense.
- Why It Was a Fragment: The original word group is a participial phrase beginning with stretching; it lacks both a subject and a finite main verb.
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- Correctly Punctuated Sentence: Have you changed the drill bit?
- Why It Is a Sentence: This is a complete interrogative sentence (question) with the subject you and the verb phrase Have changed. Capitalize Have and add a question mark.
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- Revised Sentence: To estimate expenses accurately for the next three quarters of this fiscal year, we need the figures from the accountant.
- Why It Was a Fragment: An infinitive phrase beginning with to estimate cannot serve as the main verb of a sentence; adding the independent clause we need the figures from the accountant completes the thought.
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- Revised Sentence (Option A — Adding an Independent Clause): They found problems when they swam under the boat and checked the hull.
- Revised Sentence (Option B — Deleting "when"): They swam under the boat and checked the hull.
- Why It Was a Fragment: Because it begins with the subordinating conjunction when, it is a subordinate clause that cannot stand alone.
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- Revised Sentence: We will see the play at the Paramount Theater, one of the only buildings from this period still in use today.
- Why It Was a Fragment: The original word group is a noun phrase with modifiers and prepositional phrases, but it has no verb.
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- Revised Sentence: The Garlic Festival is an event held but once a year and eagerly anticipated by the population of this small rural county.
- Why It Was a Fragment: The participles held and anticipated modify event as adjectives; the word group lacks a subject and a main verb (supplied by adding The Garlic Festival is).
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- Correctly Punctuated Sentence: Take this as an example.
- Why It Is a Sentence: This is an imperative sentence (command/request). Its verb is Take, and its understood subject is (you).
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- Correctly Punctuated Sentence: Covering the portrait's face with a few diagonal pink pastel strokes was the bold act of a creative genius.
- Why It Is a Sentence: Unlike Item 2, where the -ing phrase had no main verb, here the entire gerund phrase Covering the portrait's face with a few diagonal pink pastel strokes serves as the subject of the linking verb was!
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- Correctly Punctuated Sentence: How surprised we all were at the news!
- Why It Is a Sentence: This is a complete exclamatory sentence with the subject we, the linking verb were, and the predicate adjective surprised (modified by the adverb How). Capitalize How and add an exclamation point.
Frequently Asked Questions (FAQ)
Both items begin with an -ing verbal phrase, but in Item 2 ("stretching in a seemingly endless blue expanse from the coast of Peru to the Great Barrier Reef"), there is no main verb or subject anywhere in the word group. In Item 9, the -ing gerund phrase ("Covering the portrait's face with a few diagonal pink pastel strokes") is immediately followed by the linking verb was and the predicate nominative act, making it a complete sentence.
Item 1 is an inverted sentence in which the verb lay comes before its compound subject, stacks and stacks. If you rearrange the sentence into standard subject-verb order—"Stacks and stacks of dusty magazines, each a collector's prize, lay here in the basement of the library"—you can clearly see that it contains a subject, a verb, and a complete thought.
In a question, the helping verb comes before the subject (e.g., "How surprised were we?"). In Item 10, the subject we comes before the verb were ("How surprised we all were at the news!"), which is the standard word order for an exclamatory sentence expressing strong emotion.