Words can do many jobs. They can tell a fact, ask a question, give a command, or show a strong feeling. When words are put together to express a complete thought, they make a sentence. Good writers and speakers choose the kind of sentence that matches what they want to say.
A sentence is a group of words that expresses a complete thought. A sentence begins with a capital letter. A sentence also ends with the correct punctuation mark.
A complete sentence usually has a naming part and a telling part. The naming part tells who or what the sentence is about. The telling part tells what that person, animal, or thing does or is.
Look at these examples:
The dog runs. This is a complete sentence.
Runs fast. This is not a complete sentence because we do not know who runs.
The yellow dog runs fast. This is a complete sentence with more detail.
A simple sentence expresses one complete thought. A compound sentence joins two complete thoughts. The four kinds of sentences are declarative, interrogative, imperative, and exclamatory.
When you write, you want your reader to understand your whole idea. That is why complete sentences matter. Even short sentences can be strong if they are complete.
A declarative sentence tells something. It gives information. It ends with a period.
Examples: I have a red hat. The cat is sleeping. We play at recess.
An interrogative sentence asks something. It ends with a question mark.
Examples: Do you have a red hat? Where is the cat? Can we play now?
An imperative sentence tells someone to do something. It can be a command or a polite request. It usually ends with a period.
Examples: Put on your hat. Please close the door. Line up quietly.
An exclamatory sentence shows strong feeling. It ends with an exclamation mark.
Examples: What a big dog! I am so happy! That was a fast run!
Matching the kind of sentence to the job
Step 1: If you want to tell something, use a declarative sentence.
Example: The sun is bright.
Step 2: If you want to ask something, use an interrogative sentence.
Example: Is the sun bright?
Step 3: If you want to tell someone what to do, use an imperative sentence.
Example: Look at the sun.
Step 4: If you want to show a strong feeling, use an exclamatory sentence.
Example: What a bright sun!
Notice that the same topic can be written in different ways. The words and punctuation change because the job of the sentence changes.
A simple sentence has one complete thought. It may be short or long, but it stays one complete idea.
Short simple sentences: Birds sing. Mom cooks. I smile.
Longer simple sentences: The little birds sing in the tree. My mom cooks soup for dinner. I smile when I see my friend.
Each one is still a simple sentence because it tells just one complete thought.
Remember that a sentence starts with a capital letter and ends with punctuation. A name like Sam or a word at the beginning of a sentence needs a capital letter.
Simple sentences are helpful when you want your writing to be clear. They are easy to read and easy to understand.
A compound sentence has two complete thoughts joined together. You can join them with words such as and, but, or so.
Look at the two simple sentences: I drew a picture. I colored the sky blue.
You can join them to make a compound sentence: I drew a picture, and I colored the sky blue.
Here are more examples:
We went outside, and we played tag.
I was tired, but I finished my work.
It started to rain, so we went inside.
How compound sentences work
Each part of a compound sentence can stand alone as its own sentence. When the parts are joined, the new sentence shares two connected ideas. The joining word helps the reader know the relationship. And adds, but shows a difference, and so shows a result.
Compound sentences help you say more. Instead of writing many short sentences in a row, you can connect ideas smoothly.
Sometimes a sentence is complete, but it can be made more interesting by adding details. This is called expanding a sentence.
Start with: The girl runs.
You can expand it: The girl runs fast.
Add more: The happy girl runs fast on the playground.
Add when: The happy girl runs fast on the playground after lunch.
The sentence is still one complete thought, but now it paints a clearer picture.
You can expand a sentence by adding words that tell:
Growing a sentence
Step 1: Start with a simple sentence.
The boy jumps.
Step 2: Add a describing word.
The tall boy jumps.
Step 3: Add how or where.
The tall boy jumps high on the grass.
Step 4: Add when.
The tall boy jumps high on the grass at recess.
Writers expand sentences so readers can see, hear, and understand the idea better.
A prompt is something that tells you what to say or write. When you answer a prompt, choose the sentence type that fits best.
If the prompt asks you to tell about your pet, a declarative sentence works well. Example: My pet rabbit likes carrots.
If the prompt asks you to ask your teacher something, write an interrogative sentence. Example: May I sharpen my pencil?
If the prompt tells you to give directions, use an imperative sentence. Example: Turn the page.
If the prompt asks you to show excitement, use an exclamatory sentence. Example: This game is so much fun!
One set of words can change its job with new punctuation and a small word change. You are here. tells something, but Are you here? asks something.
You can also answer prompts with simple or compound sentences. If the prompt needs one clear idea, a simple sentence may be best. If you want to share two connected ideas, a compound sentence can be a better choice.
For example, if the prompt is about what you do after school, you might write a simple sentence: I read books after school. You might also write a compound sentence: I read books after school, and I play with my sister.
When you speak, your voice helps show whether you are telling, asking, commanding, or exclaiming. When you write, punctuation does that job.
Be careful to use the right end mark:
Also remember to use a capital letter at the beginning of every sentence. If you write a name like Ana, Ben, or Kai, that name needs a capital letter too.
| Sentence kind | Job | End mark | Example |
|---|---|---|---|
| Declarative | Tells | Period | The fish swims. |
| Interrogative | Asks | Question mark | Does the fish swim? |
| Imperative | Commands or requests | Period | Feed the fish. |
| Exclamatory | Shows strong feeling | Exclamation mark | What a pretty fish! |
Table 1. A comparison of the four kinds of sentences, their jobs, punctuation, and examples.
Careful sentence writing helps your ideas make sense. It helps readers know exactly what you mean. When you choose the right sentence type, write a complete thought, and add details, your writing becomes stronger and clearer.
