Sentence Combining | Open Textbooks

📖 Learn

Good writers know how to combine short, choppy sentences into smooth, flowing ones. This skill makes your writing easier to read and more interesting. Let's learn how to become a sentence-combining pro!

Why Combine Sentences?

🌊

Better Flow

Combined sentences read smoothly, like a gentle river instead of choppy waves.

🎨

More Variety

Mixing sentence lengths keeps readers interested and engaged.

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Avoid Choppiness

Too many short sentences in a row can make writing feel bumpy and boring.

See the Difference

Choppy Writing:

I have a dog. His name is Max. He likes to play fetch. He is very friendly.

Smooth Writing:

I have a friendly dog named Max who loves to play fetch.

Notice how combining sentences makes the writing flow better and sounds more natural!

Meet the FANBOYS!

The 7 coordinating conjunctions that join sentences of equal importance

F A N B O Y S

For

explains why

"I brought an umbrella, for it might rain."

And

adds information

"I like pizza, and my brother likes tacos."

Nor

adds negative

"I don't like spinach, nor do I like broccoli."

But

shows contrast

"I studied hard, but the test was still difficult."

Or

gives a choice

"We can go to the park, or we can stay home."

Yet

shows surprise

"She is young, yet she plays piano beautifully."

So

shows result

"I was tired, so I went to bed early."

📌 Subordinating Conjunctions

These words make one idea depend on another. They show relationships like time, cause, or condition.

because although when while if since after before unless

Two Sentences:

It started raining. We went inside.

Combined:

When it started raining, we went inside.

📌 Relative Pronouns

These words add extra information about a noun. They help you describe people, places, or things in the same sentence.

who whom which that whose

Two Sentences:

My teacher is very kind. She helps me with math.

Combined:

My teacher, who helps me with math, is very kind.

📝 Comma Rules When Combining

Knowing when to use a comma is important! Here are the key rules:

Rule 1: FANBOYS need a comma BEFORE them

"I like soccer, but my sister prefers basketball."

Rule 2: Subordinating conjunctions at the START need a comma after the first part

"Although it was cold, we went swimming."

Rule 3: Subordinating conjunctions in the MIDDLE usually don't need a comma

"We went swimming although it was cold." (no comma needed)

Rule 4: Extra information with "who" or "which" uses commas around it

"My dog, who loves treats, learned a new trick."

💡 Pro Tip

Read your combined sentence out loud! If it sounds natural and makes sense, you've done it right. If it sounds confusing, try a different conjunction or rearrange the parts.

💡 Examples

Let's look at pairs of choppy sentences and see different ways to combine them.

Example 1

Choppy:

I like pizza. My sister likes pasta.

Combined with FANBOYS (but):

I like pizza, but my sister likes pasta.

Combined with subordinating conjunction (while):

While I like pizza, my sister likes pasta.

Both versions work! "But" shows contrast directly, while "while" suggests they have different preferences at the same time.

Example 2

Choppy:

The book was exciting. I couldn't put it down.

Combined with FANBOYS (so):

The book was exciting, so I couldn't put it down.

Combined with subordinating conjunction (because):

Because the book was exciting, I couldn't put it down.

"So" shows the result, while "because" shows the reason. Both clearly connect the two ideas!

Example 3

Choppy:

The scientist made a discovery. She won an award. The discovery changed medicine.

Combined with relative pronoun (who, that):

The scientist, who made a discovery that changed medicine, won an award.

We combined THREE sentences into one! "Who" tells us more about the scientist, and "that" tells us more about the discovery.

✏️ Practice

Now it's your turn! Choose the best way to combine each pair of sentences.

Question 1

Combine: "The storm was scary. We stayed calm."

Question 2

Which conjunction fits best? "I finished my homework _____ I could go outside and play."

Question 3

Combine: "My grandmother is 80 years old. She still runs marathons."

Question 4

Which sentence is combined correctly?

✅ Check Your Understanding

Play "Sentence Builder" to test your sentence combining skills!

🏗️ Sentence Builder Challenge

Combine sentences or identify correct combinations

Score: 0/6 Question: 1/6

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🚀 Summary & Next Steps

🎯

FANBOYS

For, And, Nor, But, Or, Yet, So

🔗

Subordinating

because, although, when, while, if

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Relative

who, which, that

✏️

Commas

Use them with FANBOYS and at clause boundaries

💡 Keep Practicing!

Look for choppy sentences in your own writing and try combining them
When reading, notice how authors combine sentences
Practice using different conjunctions to see how meaning changes
Remember: Variety is key! Mix short and combined sentences

Continue Learning

Review Word Choice to learn about selecting strong words
Return to the Revision Strategies unit overview
Practice sentence combining in your next writing assignment