Sentences in English: Definition, Structures, Types and Examples

A sentence is the basic unit of written English. It starts with a capital letter, ends with a full stop (period), a question mark or an exclamation mark, and expresses a complete thought.

In this guide, you’ll learn what makes a sentence complete, the four sentence structures (simple, compound, complex and compound-complex), the four types of sentences (declarative, interrogative, imperative and exclamatory), and how to avoid the most common sentence mistakes.

What Is a Sentence?

A sentence is a group of words that expresses a complete thought. Every complete sentence has two main parts: a subject (who or what the sentence is about) and a predicate (what the subject does or is). The predicate always contains a verb. Britannica describes the sentence as a fundamental unit of language.

Rules of a Complete Sentence

• It starts with a capital letter.
• It ends with a full stop (.), a question mark (?) or an exclamation mark (!).
• It has a subject and a verb. In commands, the subject you is understood: Sit down.
• It expresses a complete thought that makes sense on its own.

Phrases, Clauses and Sentences

The happy cat is not a sentence. It is a phrase: a group of words without a subject and verb. It doesn’t tell us anything about the cat. Add a verb and it becomes a sentence: The happy cat is sleeping.

• Phrase: a group of words with no subject–verb pair: in the morning, the tall boy
• Clause: a group of words with a subject and a verb. An independent clause can stand alone (it was raining); a dependent clause cannot (because it was raining). Learn more about independent and dependent clauses.
• Sentence: one or more clauses that express a complete thought: We stayed inside because it was raining.

Sentence Examples

• Smith was a good king.
• Robert had a great army.
• She loves her new pets.
• We drink coffee every evening.
• Does he play football?
• Did they build a good house?
• Isn’t Mia playing with her doll?
• I have not finished my homework.
• What a beautiful garden you have!
• Please close the window.

The 4 Sentence Structures

Sentence structure describes how a sentence is built: how many independent and dependent clauses it has. There are four sentence structures:

1. Simple Sentences

A simple sentence has one independent clause and no dependent clauses. It can still have more than one subject or more than one verb. Tom and Sara sang and danced has two subjects and two verbs, but it is still one clause, so it is a simple sentence.

Simple Sentence Examples

• William waited for the bus.
• Sophia stood on her tiptoes.
• The truck turned the corner.
• Isabella twirled in circles.
• She cooked dinner.
• Oliver painted a picture.
• I can’t drink warm milk.
• My brother and I play tennis on Saturdays.
• The children laughed and clapped.
• He likes apples.

2. Compound Sentences

A compound sentence has two or more independent clauses. Each clause could be a sentence on its own. You can join them in three ways:

• with a comma + a coordinating conjunction (for, and, nor, but, or, yet, so): This car is too expensive, and that car is too small.
• with a semicolon: Paris is my favorite city; I visit it every year.
• with a semicolon + a conjunctive adverb + a comma: He studied hard; therefore, he passed.

A comma on its own is not enough. I like coffee, Mia likes tea is a mistake called a comma splice.

Compound Sentence Examples

• I want the sporty black bike, but I will rent the practical red one.
• Amelia needs to go to work, but she is too sick to drive.
• He didn’t want to go to the party, yet he went anyway.
• Paris is my favorite city; I plan to spend three weeks there next month.
• She only paints with bright colors; indeed, she does not like pastels at all.
• I like coffee, and Mia likes tea.
• Our bike broke down, so we finished last.
• He studied very hard; therefore, he passed his exams.
• You can walk to school, or you can take the bus.

3. Complex Sentences

A complex sentence has one independent clause and at least one dependent clause. The dependent clause usually starts with a subordinating conjunction such as because, although, when, if, while, after, before, unless or since, or with a relative pronoun such as who, which or that.

When the dependent clause comes first, put a comma after it: Because it was raining, we stayed inside. When it comes second, you usually don’t need a comma: We stayed inside because it was raining.

Complex Sentence Examples

• Amelia missed her exam because she was late. (independent clause: Amelia missed her exam; dependent clause: because she was late)
• Because my coffee was too hot, I added some cold milk.
• Although she was wealthy, she was still unhappy.
• They returned the computer after they noticed it was damaged.
• Whenever prices go down, customers buy more.
• When Isabella was younger, she believed in fairy tales.
• We didn’t enjoy the play even though the acting was good.
• After the rain fell, the desert smelled fresh.
• Lily worked on the surprise gift while her father was out.
• The boy who lives next door is my best friend.

4. Compound-Complex Sentences

A compound-complex sentence combines both structures. It has at least two independent clauses, like a compound sentence, and at least one dependent clause, like a complex sentence.

Compound-Complex Sentence Examples

• Sebastian loves his sister, and she loves him because he always helps her.
• The dog ran off when I opened the gate, but it came back an hour later.
• When Maria went to the shop, she wanted to buy some milk, but she didn’t have enough money.
• The child will never eat mangoes even if he is hungry, but he always eats bananas.
• The woman was rude because she was lonely, but her attitude only made things worse.
• It is important to vote when the time comes, or you won’t have a say in new laws.
• Orla left the concert early because the music was too loud, and her friends went with her.
• Harrison likes to sleep late, but he can get up early if he has work.

The 4 Types of Sentences

Sentence type describes the purpose of a sentence: what it does. Each type has its own end punctuation:

1. Declarative Sentences

A declarative sentence makes a statement. It gives information, describes something or expresses an opinion, and it ends with a full stop. Declarative sentences can be positive or negative, and they are the most common type of sentence in English.

Declarative Sentence Examples

• Maisie loves eating chocolate.
• I am excited about the holiday.
• Her brother is smartly dressed.
• The girls walked home.
• Hudson loves honey.
• My father is a doctor.
• I do not like tea.
• They did not watch a movie last night.
• I bought a pair of shoes at the mall.
• The Earth goes around the Sun.

2. Interrogative Sentences

An interrogative sentence asks a question and always ends with a question mark. Yes/no questions start with a helping verb such as do, does, did, is, are, have, can or will. Information questions start with a question word such as who, what, where, when, why, how, whose or which.

Interrogative Sentence Examples

• How do you sew a button on a shirt?
• When is the best time to go shopping?
• Where is your new dog?
• Why is the sky blue?
• How are you today?
• Did you finish your assignment?
• Do you know the answers to the grammar exercise?
• Why did Billie arrive late?
• Whose cookies are these?
• How do you open this box?

3. Imperative Sentences

An imperative sentence gives a command, request, instruction or piece of advice. The subject you is usually not written. Imperative sentences end with a full stop, or with an exclamation mark for strong commands. Add please to make a request polite.

Imperative Sentence Examples

• Find my shoes.
• Please pass the salt.
• Get out of my way!
• Shut the door.
• Be there at seven.
• Wash your hands before dinner.
• Finish your homework by tomorrow.
• Try the black jacket.
• Don’t touch the stove!
• Turn left at the traffic lights.

4. Exclamatory Sentences

An exclamatory sentence shows strong feeling, such as surprise, joy or anger, and ends with an exclamation mark. Many start with What a… or How…, and some begin with an interjection such as Wow or Oh.

Exclamatory Sentence Examples

• Wow, she got a law degree!
• What a great day!
• I got the concert tickets!
• How well he dances!
• What a sad ending!
• I’m so happy right now!
• That’s such a beautiful ring!
• What a surprise!

Here is a printable summary of the four types of sentences:

Sentence Structure vs Sentence Type

Every sentence has both a structure and a type. The structure tells you how the sentence is built; the type tells you what it does:

Sentence	Structure	Type
The bus is late.	Simple	Declarative
Is the bus late again?	Simple	Interrogative
Close the window because it is cold.	Complex	Imperative
We won the match, and I scored the winning goal!	Compound	Exclamatory
Did you call her after you got home, or did you forget?	Compound-complex	Interrogative

Common Sentence Mistakes

Mistake	Wrong	Right
Sentence fragment	Because I was tired.	I went to bed early because I was tired.
Run-on sentence	I love pizza I eat it every week.	I love pizza, so I eat it every week.
Comma splice	I like coffee, Mia likes tea.	I like coffee, but Mia likes tea.
Subject–verb agreement	She love her new pets.	She loves her new pets.
Missing subject	Went to the market yesterday.	We went to the market yesterday.
Wrong end punctuation	Where do you live.	Where do you live?

Frequently Asked Questions

What are the 4 types of sentences?

The four types of sentences are declarative (statements), interrogative (questions), imperative (commands and requests) and exclamatory (strong feelings).

What are the 4 sentence structures?

The four sentence structures are simple (one independent clause), compound (two or more independent clauses), complex (one independent clause and at least one dependent clause) and compound-complex (two or more independent clauses and at least one dependent clause).

What is the difference between sentence types and sentence structures?

Sentence types are about purpose: making a statement, asking a question, giving a command or showing feeling. Sentence structures are about how the sentence is built from clauses. Every sentence has one of each.

What makes a sentence complete?

A complete sentence has a subject, a verb and a complete thought. It starts with a capital letter and ends with a full stop, a question mark or an exclamation mark.

Can a sentence be just one word?

Yes. Imperative sentences can be one word, such as Stop! or Listen., because the subject you is understood.

What is the difference between a compound and a complex sentence?

A compound sentence joins two independent clauses (I was tired, so I went to bed). A complex sentence joins an independent clause and a dependent clause (I went to bed because I was tired).

What is a sentence fragment?

A fragment is a group of words that looks like a sentence but is not complete, usually because it is missing a subject or a verb or does not express a complete thought: Because I was tired.

Practice Sentence Types and Structures

Test yourself with our free sentence structures quiz, then practice with these printable types of sentences worksheets and sentence structures worksheets. To build better sentences, read our guides to the nine parts of speech, the 12 verb tenses and active and passive voice.

Have a question about sentences? Leave a comment below and we’ll get back to you as soon as we can.