Have you ever written something like “under the table” and wondered whether it counts as a complete sentence? It makes sense, but it does not have the same grammatical structure as “The cat is sleeping under the table.”
That is the main question behind phrase vs. sentence.
A phrase and a sentence both use words to express meaning. However, they work at different levels of English grammar. A phrase is a grammatical building block, while a sentence is a complete grammatical unit used to make a statement, ask a question, give a command, or express strong feelings.
Consider these examples:
- The little brown puppy — Noun phrase
- Behind the wooden fence — Prepositional phrase
- The puppy barked loudly. — Complete sentence
- Did the puppy bark? — Complete question
- Please feed the puppy. — Complete command
Understanding the difference helps you identify sentence fragments, use punctuation correctly, and write clearer sentences for school, work, and everyday communication.
This guide explains phrase vs sentence with easy rules, comparison charts, 40 numbered examples, sentence types, common mistakes, a practice quiz, and helpful FAQs.
Quick Answer: Phrase vs. Sentence
A phrase is a grammatical unit built around a main word, called its head. Examples include the blue bicycle, under the bed, and very happy.
A sentence is a complete grammatical unit that normally contains at least one independent clause. It can make a statement, ask a question, give a command, or express an exclamation.
Compare:
- After school — Phrase
- We played after school. — Sentence
- The old house — Phrase
- The old house needs repairs. — Sentence
Easy rule: A phrase is a building block. A sentence is a complete grammatical unit.
A phrase can still communicate useful information when used alone in conversation. For example, “After lunch.” is a natural answer to “When should we meet?” However, it remains a prepositional phrase rather than an ordinary independent clause.
TL;DR: Phrase vs. Sentence
- Phrase: A grammatical unit organized around a head word.
- Sentence: A complete grammatical unit used to communicate.
- Phrases often function as subjects, objects, modifiers, or complements within sentences.
- Sentences normally contain at least one independent clause.
- Verb phrases can contain verbs without being complete sentences.
- Imperative sentences may have an understood subject, as in “Stop!”
- Conversational fragments can be natural even when they are not complete independent clauses.
| Feature | Phrase | Sentence |
|---|---|---|
| Main structure | Organized around a head word | Complete grammatical structure |
| Main function | Performs a grammatical role | Communicates a complete grammatical message |
| Subject required? | No | Not always expressed |
| Can contain a verb? | Yes | Normally contains a predicate |
| Can contain a clause? | Yes | Yes |
| Stands alone in formal writing? | Usually not as a complete sentence | Yes |
| Example | The happy child | The happy child laughed. |
Phrase vs. Sentence: The Main Difference
The most important difference between a phrase and a sentence is their grammatical structure.
A phrase is organized around a head word. A sentence is a complete grammatical unit that usually contains an independent clause.
Compare these two expressions:
Phrase: The little girl in the garden
Sentence: The little girl in the garden smiled.
The first expression is a noun phrase. It identifies a person but does not contain a complete independent clause.
The second expression is a complete declarative sentence because it includes the subject the little girl in the garden and the predicate smiled.
Side-by-Side Examples
| Phrase | Complete sentence |
|---|---|
| The friendly neighbor | The friendly neighbor waved. |
| Under the kitchen table | The puppy slept under the kitchen table. |
| Before sunrise | We left before sunrise. |
| Extremely tired | The runners were extremely tired. |
| Near the school | A new library opened near the school. |
| The broken window | The broken window needs repairs. |
Why the Difference Matters
A phrase may sound meaningful without being a complete sentence.
For example:
Fragment: The student beside the window.
Complete sentence: The student beside the window raised her hand.
The second version adds a predicate and forms a complete independent clause.
Key takeaway: A phrase and a sentence are not opposites. A sentence can contain many phrases, and a phrase can sometimes contain an embedded clause.
What Is a Phrase in English Grammar?
A phrase is a grammatical unit organized around a word called its head.
The head helps determine the phrase’s type and grammatical function.
A phrase may consist of one word or several words.
Noun Phrase
The bright yellow flowers are blooming.
The head of the highlighted noun phrase is flowers.
Verb Phrase
She has been studying all afternoon.
The highlighted words form a verb phrase.
Adjective Phrase
The instructions were very helpful.
The head of the adjective phrase is helpful.
Adverb Phrase
The teacher spoke quite clearly.
The head of the adverb phrase is clearly.
Prepositional Phrase
The keys are inside the drawer.
The head is the preposition inside.
Can a Phrase Be One Word?
Yes. In many grammar frameworks, a single word can function as a phrase.
For example:
Students arrived early.
Here, students functions as a noun phrase.
Can a Phrase Contain a Clause?
Yes.
Consider:
The book that you recommended is excellent.
The highlighted noun phrase contains the relative clause that you recommended.
This is why defining a phrase simply as a group of words without a subject and verb is not fully accurate.
Remember: A phrase is identified by its grammatical structure and function, not only by the number of words it contains.
What Is a Sentence in English Grammar?
A sentence is a complete grammatical unit used to make a statement, ask a question, give a command, or express an exclamation.
In written English, a sentence normally begins with a capital letter and ends with a period, question mark, or exclamation point.
Declarative Sentence
The children are playing outside.
This sentence makes a statement.
Interrogative Sentence
Are the children playing outside?
This sentence asks a question.
Imperative Sentence
Please close the window.
This sentence makes a request.
Its subject, you, is understood.
Exclamatory Sentence
What a beautiful day!
This is an exclamatory sentence expressing strong feeling.
Does Every Sentence Have a Written Subject?
No.
Consider:
Stop!
This is a complete imperative sentence. Its understood subject is you.
Does Every Complete Response Count as a Sentence?
Not necessarily.
Consider this conversation:
Question: Where are your shoes?
Answer: Under the bed.
The answer communicates the necessary information, but under the bed remains a prepositional phrase.
It is a complete conversational response, not an ordinary independent clause.
Sentence Types by Purpose
| Sentence type | Example | Purpose |
|---|---|---|
| Declarative | The store opens at nine. | Makes a statement |
| Interrogative | Does the store open at nine? | Asks a question |
| Imperative | Open the door. | Gives a command |
| Exclamatory | What a wonderful surprise! | Expresses strong feeling |
Important: A complete grammatical sentence and a complete conversational response are not always the same thing.
Phrase vs. Sentence Comparison Chart
The following chart summarizes the differences between phrases and sentences.
| Question | Phrase | Sentence |
|---|---|---|
| What is its main structure? | Organized around a head | Complete grammatical structure |
| Must it have a subject? | No | May have an understood subject |
| Can it contain a verb? | Yes | Normally contains a predicate |
| Can it contain another phrase? | Yes | Yes |
| Can it contain a clause? | Yes | Yes |
| Does it normally stand alone in formal prose? | No | Yes |
| Example | The old wooden house | The old wooden house collapsed. |
Phrase Example
The beautiful red flowers
This is a noun phrase.
Sentence Example
The beautiful red flowers are blooming.
This is a complete declarative sentence.
Phrase Inside a Sentence
The young teacher placed the books on the desk.
This sentence contains several phrases.
A Clause Inside a Phrase
The student who won the competition smiled.
The highlighted noun phrase contains the relative clause who won the competition.
Does a Period Make a Phrase a Sentence?
No.
Under the table.
Adding a period does not automatically create a complete independent clause.
The puppy slept under the table.
This version contains a complete independent clause.
Writing tip: Judge sentence completeness by grammatical structure, not punctuation alone.
How to Identify a Phrase in a Sentence
You can identify a phrase by looking for a grammatical unit organized around a head word.
Step 1: Find the Head Word
The friendly teacher smiled.
The head is teacher.
Step 2: Identify the Phrase Type
She has been working all morning.
The highlighted words form a verb phrase.
Step 3: Look for Modifiers
The movie was extremely interesting.
The head is interesting, modified by extremely.
Step 4: Identify Prepositional Phrases
The dog slept beside the fireplace.
The preposition beside heads the phrase.
Step 5: Identify Its Function
The young musician played in the auditorium.
The first highlighted phrase functions as the subject.
The second provides information about location.
Step 6: Check for Embedded Clauses
The student who answered correctly received a prize.
The highlighted expression is a noun phrase containing the relative clause who answered correctly.
Quick Phrase Checklist
Ask yourself:
- What is the head word?
- Which words belong to the same grammatical unit?
- What role does the phrase play?
- Does it contain an embedded phrase or clause?
Key takeaway: Phrases are not always short, and they do not always exclude verbs or clauses.
How to Identify a Complete Sentence
To identify a complete sentence, look for a complete grammatical structure.
Most complete sentences contain at least one independent clause.
Step 1: Find the Predicate
The teacher explained the lesson.
The predicate is explained the lesson.
Step 2: Find the Subject
The teacher explained the lesson.
The subject is the teacher.
Step 3: Check for an Independent Clause
The students completed their homework.
This is a complete sentence.
Step 4: Watch for Dependent Clauses
Because the students completed their homework
This is a dependent clause.
It normally cannot stand alone as a complete sentence in formal writing.
Complete version:
Because the students completed their homework, they could relax.
Step 5: Recognize Imperative Sentences
Close the door.
This is a complete imperative sentence.
The subject you is understood.
Step 6: Check the Intended Use
Consider:
After dinner.
As a standalone statement in formal writing, this is usually a fragment.
As an answer to “When should we meet?”, it is natural and complete for that conversation.
Complete Sentence Checklist
A complete sentence generally:
- Has an independent clause or another recognized complete sentence construction.
- Contains a predicate, with an expressed or understood subject where appropriate.
- Communicates a statement, question, command, or exclamation.
- Uses suitable capitalization and ending punctuation in writing.
Remember: Sentence completeness depends on grammatical structure and context, not simply on word count.
20 Examples of Phrases in Sentences
The following examples show five common phrase types. The bold words identify the phrases being studied.
Noun Phrases
- The little brown puppy slept on the rug.
- A beautiful flower garden surrounds the house.
- My favorite English teacher explained the lesson.
- The old wooden chair needs repairs.
Verb Phrases
- She has been studying all morning.
- They will be traveling next week.
- He might have forgotten his appointment.
- We are preparing dinner.
Adjective Phrases
- The movie was really exciting.
- She felt extremely nervous.
- The instructions were quite simple.
- He looked very tired.
Adverb Phrases
- She answered very politely.
- He finished the assignment quite quickly.
- They worked extremely carefully.
- The baby slept rather peacefully.
Prepositional Phrases
- The keys are under the sofa.
- She arrived before sunset.
- The children played in the backyard.
- We walked along the river.
What These Examples Teach
Every complete example above is a sentence, but the bold portion is a phrase.
For instance:
She has been studying all morning.
The highlighted words are a verb phrase. The full sentence also contains the subject she.
Important: A phrase can be part of a complete sentence without being a complete sentence by itself.
20 Examples of Complete Sentences
These examples demonstrate the four main sentence purposes and several sentence structures.
Declarative Sentences
- The sun is shining brightly.
- She enjoys reading mystery novels.
- The children are playing outside.
- We completed the project yesterday.
- The teacher explained the lesson clearly.
Interrogative Sentences
- Where are you going?
- Did you finish your homework?
- Why is the baby crying?
- Have they arrived yet?
- What time does the meeting begin?
Imperative Sentences
- Please close the door.
- Turn off the lights.
- Read the instructions carefully.
- Take your time.
- Call me when you arrive.
Exclamatory Sentences
- What a beautiful day!
- That was an amazing performance!
- How quickly time passes!
- What a wonderful surprise!
- We finally won the game!
Examples by Sentence Structure
A sentence can also be classified by the number and types of clauses it contains.
| Structure | Example |
|---|---|
| Simple | The baby slept. |
| Compound | The baby slept, and her parents rested. |
| Complex | The baby slept because she was tired. |
| Compound-complex | The baby slept because she was tired, and her parents rested. |
Key takeaway: Sentence purpose tells us what a sentence does. Sentence structure tells us how its clauses are arranged.
Types of Phrases in English Grammar
English includes several important phrase categories.
Noun Phrases
A noun phrase is organized around a noun or another nominal head.
Example:
The talented musician performed.
Verb Phrases
A verb phrase is organized around a verb.
Example:
She has been reading.
Adjective Phrases
An adjective phrase is organized around an adjective.
Example:
The story was very interesting.
Adverb Phrases
An adverb phrase is organized around an adverb.
Example:
He answered quite confidently.
Prepositional Phrases
A prepositional phrase is organized around a preposition.
Example:
The dog slept beside the fireplace.
Infinitive Constructions
Traditional school grammar often uses the term infinitive phrase.
Example:
She wants to learn Spanish.
Many modern grammars analyze to learn Spanish as a nonfinite clause.
Participial Constructions
Traditional grammar often calls these participial phrases.
Example:
Walking through the park, she noticed a bird.
Modern grammar may classify the highlighted construction as a nonfinite clause.
Gerund Constructions
Traditional grammar often uses the term gerund phrase.
Example:
Reading books improves vocabulary.
Many modern analyses treat reading books as a nonfinite clause functioning as the subject.
Phrase Types Chart
| Type | Example | Main function |
|---|---|---|
| Noun phrase | The tall student | Names or identifies |
| Verb phrase | Has been studying | Expresses verbal meaning |
| Adjective phrase | Very happy | Describes |
| Adverb phrase | Quite quickly | Modifies |
| Prepositional phrase | Under the table | Expresses a relationship |
| Infinitive construction | To learn Spanish | Expresses an action or purpose |
| Participial construction | Walking home | Adds information |
| Gerund construction | Reading books | Can function as a subject or complement |
Grammar note: Traditional and modern grammar frameworks sometimes classify nonfinite constructions differently. Both sets of labels may appear in educational materials.
Types of Sentences in English Grammar
Sentences can be classified in two main ways: by purpose and by structure.
Sentence Types by Purpose
Declarative sentence: Makes a statement.
The library closes at six.
Interrogative sentence: Asks a question.
Does the library close at six?
Imperative sentence: Gives a command, instruction, or request.
Please return the book.
Exclamatory sentence: Expresses strong feeling.
What an exciting story!
Sentence Types by Structure
Simple sentence: Contains one independent clause.
The children played outside.
Compound sentence: Contains at least two independent clauses.
The children played, and their parents watched.
Complex sentence: Contains an independent clause and at least one dependent clause.
The children played because the weather was pleasant.
Compound-complex sentence: Contains at least two independent clauses and at least one dependent clause.
The children played because the weather was pleasant, and their parents watched.
Sentence Structure Comparison
| Type | Independent clauses | Dependent clauses |
|---|---|---|
| Simple | One | None |
| Compound | Two or more | None |
| Complex | At least one | At least one |
| Compound-complex | Two or more | At least one |
Can a Sentence Belong to Two Categories?
Yes.
Consider:
Why did you leave when the meeting ended?
This is an interrogative sentence because it asks a question.
It is also a complex sentence because it contains the dependent clause when the meeting ended.
Important: Sentence purpose and sentence structure describe different features.
One-Word Sentences vs. One-Word Responses
A common question in English grammar is whether a single word can be a complete sentence.
The answer depends on the word’s grammatical function and context.
One-Word Imperative Sentences
Stop!
Run!
Listen!
These are complete imperative sentences.
The subject you is understood.
One-Word Conversational Responses
Consider:
Question: Are you ready?
Answer: Yes.
The word yes is a response particle. It functions as a complete conversational answer, but it is not an ordinary independent clause.
One-Word Time Expressions
Question: When will you arrive?
Answer: Tomorrow.
The answer is natural in conversation.
However, tomorrow is an adverbial time expression rather than a standard independent clause.
One-Word Expressions
Thanks!
This is a conventional expression used as a complete utterance.
Its grammatical structure differs from that of a typical independent clause.
Comparison Chart
| Expression | Classification | Natural alone? |
|---|---|---|
| Stop! | Imperative sentence | Yes |
| Run! | Imperative sentence | Yes |
| Yes. | Response particle | Yes, in context |
| Thanks! | Conventional expression | Yes |
| Tomorrow. | Time expression | Yes, in context |
| Under the table. | Prepositional phrase | Yes, as a contextual answer |
The Important Difference
A word or phrase may be complete as a conversational response without having the grammatical structure of an independent clause.
Memory trick: Complete meaning in conversation does not always mean complete sentence structure.
Phrase vs. Sentence: Fragments and Complete Thoughts
A sentence fragment is a word group presented as a sentence even though it lacks the structure normally required for a complete sentence.
Fragments often occur when writers mistake phrases or dependent clauses for independent sentences.
Phrase Fragment
Fragment: The girl near the window.
This is a noun phrase.
Corrected: The girl near the window waved.
Prepositional Phrase Fragment
Fragment: After the meeting.
Corrected: We went home after the meeting.
Dependent-Clause Fragment
Fragment: Because the bus was late.
Corrected: We arrived late because the bus was late.
Missing Predicate
Fragment: The old house on the corner.
Corrected: The old house on the corner needs repairs.
Fragment Correction Table
| Fragment | Complete sentence |
|---|---|
| Under the old bridge. | The boat passed under the old bridge. |
| The little girl in the garden. | The little girl in the garden smiled. |
| After lunch. | We went outside after lunch. |
| Because it was raining. | We stayed home because it was raining. |
| When the bell rang. | The students left when the bell rang. |
Are Fragments Always Incorrect?
No.
Fragments are common in everyday conversation, advertising, headlines, dialogue, and creative writing.
For example:
Question: Where did you put the keys?
Answer: On the kitchen counter.
This response is natural.
In formal academic or professional writing, however, complete sentences are generally preferred unless a fragment is used deliberately.
How to Fix a Fragment
You can often fix a fragment by:
- Adding a subject or predicate.
- Joining a dependent clause to an independent clause.
- Combining a phrase with a complete clause.
- Rewriting the expression as a full sentence.
Writing tip: Before correcting a fragment, consider whether it is an accidental error or an intentional conversational or stylistic choice.
Phrase vs. Clause vs. Sentence
A phrase, clause, and sentence are related grammatical units, but each has a different role.
What Is a Phrase?
A phrase is a grammatical unit organized around a head word.
Example:
Under the table
What Is a Clause?
A clause contains a predicate and usually a subject.
Example:
The cat slept under the table
What Is a Sentence?
A sentence is a complete grammatical unit.
Example:
The cat slept under the table because it was tired.
Phrase vs. Clause vs. Sentence Chart
| Feature | Phrase | Clause | Sentence |
|---|---|---|---|
| Main structure | Head-based | Predicate-based | Complete grammatical unit |
| Subject required? | No | Usually, but may be understood | Not always expressed |
| Can stand alone? | Not normally as a full sentence | Independent clauses can | Yes |
| Example | In the garden | The children played | The children played in the garden. |
How They Work Together
Consider this sentence:
The young boy played in the garden because the weather was pleasant.
It contains:
- The young boy — Noun phrase
- In the garden — Prepositional phrase
- Because the weather was pleasant — Dependent clause
- The young boy played in the garden because the weather was pleasant — Complete sentence
Can a Sentence Contain Multiple Clauses?
Yes.
She finished her homework, and she watched a movie.
This sentence contains two independent clauses.
Can a Phrase Contain a Clause?
Yes.
The student who won the award smiled.
The highlighted noun phrase contains the relative clause who won the award.
Key takeaway: Phrases form grammatical units, clauses express predications, and sentences provide complete grammatical structures.
Common Phrase vs. Sentence Mistakes
Confusing phrases and sentences can lead to fragments, run-on sentences, and punctuation problems.
Common Mistakes Chart
| Problem | Incorrect or incomplete | Correct |
|---|---|---|
| Phrase fragment | The boy near the door. | The boy near the door waved. |
| Dependent-clause fragment | Because the bus was late. | We arrived late because the bus was late. |
| Run-on sentence | I called her she answered. | I called her, and she answered. |
| Comma splice | The rain stopped, we left. | The rain stopped; we left. |
| Missing introductory comma | When the rain stopped we left. | When the rain stopped, we left. |
Mistake 1: Treating a Phrase as a Complete Sentence
Incomplete in formal writing:
Under the kitchen table.
Complete:
The puppy slept under the kitchen table.
Mistake 2: Forgetting the Predicate
Incomplete:
The young student near the window.
Complete:
The young student near the window raised her hand.
Mistake 3: Leaving a Dependent Clause Alone
Incomplete:
Because I was tired.
Complete:
I went home because I was tired.
Mistake 4: Joining Independent Clauses Without Punctuation
Incorrect:
She studied hard she passed the test.
Correct:
She studied hard, and she passed the test.
Also correct:
She studied hard; she passed the test.
Mistake 5: Creating a Comma Splice
Incorrect:
The rain stopped, we went outside.
Correct:
The rain stopped, so we went outside.
Also correct:
The rain stopped; we went outside.
Mistake 6: Missing a Comma After an Introductory Clause
Incorrect:
Although it was cold we walked outside.
Correct:
Although it was cold, we walked outside.
Mistake 7: Confusing a Verb Phrase With a Sentence
Has been studying is a verb phrase.
She has been studying. is a complete sentence.
Easy Memory Tricks
- Phrase: Grammatical building block.
- Clause: Contains a predicate.
- Sentence: Complete grammatical unit.
- Fragment: Incomplete structure presented as a sentence.
- Imperative: Command with an often-understood subject.
- Dependent clause: Normally functions inside a larger sentence.
Best tip: Find the predicate, check the subject, and decide whether the structure forms an independent sentence.
Phrase vs. Sentence Practice Quiz
Choose the best answer for each question.
Questions
1. Which option is a prepositional phrase?
A. The dog barked.
B. Under the table
C. She is reading.
D. Close the door.
2. Which option is a complete declarative sentence?
A. Before the meeting
B. The little red bicycle
C. The children played outside.
D. Under the chair
3. Which option is a complete imperative sentence?
A. The blue car
B. After lunch
C. Close the window.
D. Under the bed
4. In the exchange “When will you arrive?” — “Tomorrow,” what is “Tomorrow” best described as?
A. An ordinary independent clause
B. A contextual one-word response
C. A complete imperative sentence
D. A compound sentence
5. Which option correctly fixes the fragment “Because it was raining”?
A. Because it was raining.
B. Because it was raining, we stayed inside.
C. Because it was raining, and.
D. Because it was raining, because.
6. Which sentence correctly joins two independent clauses?
A. She finished her homework she watched TV.
B. She finished her homework, she watched TV.
C. She finished her homework, and she watched TV.
D. She finished her homework because of she watched TV.
Answers and Explanations
1. B — Under the table.
It is a prepositional phrase expressing location.
2. C — The children played outside.
It contains an independent clause and communicates a complete statement.
3. C — Close the window.
This is a complete imperative sentence with the understood subject you.
4. B — A contextual one-word response.
Tomorrow is a natural answer to the question, but it is not an ordinary independent clause.
5. B — Because it was raining, we stayed inside.
The independent clause we stayed inside completes the sentence.
6. C — She finished her homework, and she watched TV.
The comma and coordinating conjunction and correctly join two independent clauses.
Answer Key
1-B | 2-C | 3-C | 4-B | 5-B | 6-C
Frequently Asked Questions
What is the main difference between a phrase and a sentence?
A phrase is a grammatical unit organized around a head word, while a sentence is a complete grammatical unit. For example, under the table is a phrase, but the cat slept under the table is a complete sentence.
Can a phrase be a complete sentence?
A phrase normally does not form a complete independent sentence in formal writing. However, phrases can function as natural conversational answers, headlines, or deliberate fragments. For example, on the table is a natural response to where are the keys?
Can a sentence contain several phrases?
Yes. Most sentences contain multiple phrases. For example, the young student studied in the library includes the noun phrase the young student and the prepositional phrase in the library.
Can a phrase contain a verb?
Yes. A verb phrase can contain a main verb and auxiliary verbs. For example, has been working is a verb phrase. Adding a subject creates the complete independent clause she has been working.
Can one word be a complete sentence?
Yes. Imperatives such as Stop! and Run! can be complete sentences because their subject you is understood. Other one-word expressions, such as yes or tomorrow, may be complete conversational responses without being ordinary independent clauses.
What are five examples of phrases?
Five examples are under the table, the old house, very happy, quite quickly, and has been working. These are examples of prepositional, noun, adjective, adverb, and verb phrases.
What are five examples of complete sentences?
Five examples are She smiled., The dog barked., Are you ready?, Close the door., and What a wonderful surprise! They include statements, a question, a command, and an exclamation.
How can I tell whether something is a phrase or a sentence?
Check the grammatical structure. A phrase is organized around a head word and usually functions within a larger structure. A sentence normally contains at least one independent clause, although commands can have understood subjects. Do not rely on punctuation alone.
Conclusion and References
Understanding phrase vs. sentence helps you recognize grammatical structure, avoid sentence fragments, and improve your writing.
A phrase is a grammatical unit organized around a head word. It can contain nouns, verbs, adjectives, adverbs, prepositions, or even embedded clauses.
A sentence is a complete grammatical unit used to make a statement, ask a question, give a command, or express an exclamation.
Remember these examples:
- Under the table — Prepositional phrase
- The little dog — Noun phrase
- The dog slept. — Complete declarative sentence
- Please close the door. — Complete imperative sentence
- The dog slept under the table. — Sentence containing a prepositional phrase
- Tomorrow. — Contextual one-word response, not an ordinary independent clause
The best way to identify the difference is to examine the structure and ask whether the words form a complete grammatical sentence or function as a phrase within a larger structure.
Final memory rule: A phrase is a grammatical building block; a sentence is a complete grammatical unit.
References
For further reading, consult these established English grammar resources: