Simple, Compound, and Complex Sentences Worksheet for 13-Year-Olds

Instructions

1. Read the quick guide before beginning.
2. Complete Sections 1–5 in order. The questions begin with basic identification and become more challenging.
3. For sentence-combining questions, use the conjunction named in the direction and add commas when needed.
4. Underline independent clauses once and dependent clauses twice when instructed.
5. Complete the optional challenge if you finish early.
6. Check your work with the answer key at the end.

Learning Goals

By the end of this worksheet, you should be able to:

• Identify simple, compound, and complex sentences.
• Recognize independent and dependent clauses.
• Use conjunctions to connect words, phrases, and clauses.
• Use coordinating conjunctions correctly.
• Combine ideas clearly in practical writing.

Quick Guide: Sentence Types

Simple sentence: Has one independent clause. It may have a compound subject or a compound verb.

• The coach smiled.
• Maya and Luis practiced and improved.

Compound sentence: Has two independent clauses joined by a comma and a coordinating conjunction.

• The bus was late, so we walked.

Complex sentence: Has one independent clause and at least one dependent clause. A dependent clause cannot stand alone as a complete sentence.

• Because the bus was late, we walked.
• We walked because the bus was late.

Conjunction: A word that connects words, phrases, or clauses.

Coordinating conjunctions: The seven coordinating conjunctions can be remembered with FANBOYS:

• For: gives a reason
• And: adds information
• Nor: adds another negative idea
• But: shows contrast
• Or: shows a choice
• Yet: shows contrast or an unexpected result
• So: shows a result

Comma reminder: Use a comma before a coordinating conjunction when it joins two complete sentences.

• Correct: I packed a lunch, and I filled my water bottle.
• Not needed: I packed a lunch and a water bottle.

Section 1: Identify the Sentence Type

Write simple, compound, or complex on each line.

1. The science team measured the plant carefully.

   Answer: ____

2. I wanted to ride my bike, but the tire was flat.

   Answer: ____

3. Although the trail was steep, we reached the viewpoint.

   Answer: ____

4. Jordan and Priya planned and organized the fundraiser.

   Answer: ____

5. The library was closing, so we returned our books.

   Answer: ____

6. When the rain stopped, the soccer game began.

   Answer: ____

7. My brother cooked dinner and washed the dishes.

   Answer: ____

8. We can watch a movie, or we can play a board game.

   Answer: ____

Section 2: Find the Clauses

For each sentence, write the independent clause and the dependent clause, if there is one. Remember that an independent clause can stand alone as a sentence.

Example: Because the store was closed, we went home.

• Independent clause: we went home
• Dependent clause: Because the store was closed

1. Since the concert was canceled, we listened to music at home.

   • Independent clause: ____
   • Dependent clause: _____

2. The class finished the project before the bell rang.

   • Independent clause: ____
   • Dependent clause: _____

3. Elena charged her phone, and she packed an extra battery.

   • Independent clause 1: _____
   • Independent clause 2: _____
   • Dependent clause: _____

4. My friends waited while I bought the tickets.

   • Independent clause: ____
   • Dependent clause: _____

5. The dog barked loudly.

   • Independent clause: ____
   • Dependent clause: _____

Section 3: Coordinating Conjunctions

A. Choose the best conjunction

Circle or write the best coordinating conjunction from the choices in parentheses.

1. I wanted to join the robotics club, __ I had soccer practice. (but, so, or)

2. We need to leave now, __ we will miss the train. (for, or, yet)

3. Sam brought pencils __ paper to the study group. (and, but, nor)

4. The recipe looked difficult, __ we tried it anyway. (yet, for, so)

5. You may submit the assignment online, __ you may hand it in tomorrow. (or, and, nor)

6. Mia did not call, __ did she send a message. (nor, but, so)

7. The sidewalk was icy, __ we walked carefully. (so, for, yet)

B. Match the purpose

Write the letter of the purpose that best matches each coordinating conjunction.

1. and _____
2. but _____
3. or _____
4. so _____
5. for _____
6. nor _____
7. yet _____

• A. shows a result
• B. gives a reason
• C. adds information
• D. shows a choice
• E. shows contrast
• F. adds another negative idea
• G. shows an unexpected contrast

Section 4: Combine the Ideas

Combine each pair of sentences into one sentence. Use the conjunction in parentheses. Add punctuation where needed.

Example: The store was crowded. We waited patiently. (but)

Answer: The store was crowded, but we waited patiently.

1. The weather was cold. We wore our coats. (so)

   ---

2. I finished my homework. I watched a television show. (and)

   ---

3. You can walk to the park. You can take the bus. (or)

   ---

4. The team practiced every day. It improved quickly. (so)

   ---

5. Leo wanted to buy the game. He had not saved enough money. (but)

   ---

6. The dog hid under the table. It was frightened by the thunder. (for)

   ---

Section 5: Build Complex Sentences

Use the word in parentheses to join each pair of ideas. You may put the dependent clause at the beginning or the end. Remember the comma rule.

Example: The picnic continued. The rain stopped. (after)

Answer: The picnic continued after the rain stopped.

1. We wore helmets. We rode our bikes. (when)

   ---

2. I will text you. I arrive at the station. (when)

   ---

3. The team celebrated. It won the final game. (because)

   ---

4. We stayed indoors. The air quality was unhealthy. (because)

   ---

5. Maya saved her work. The computer might lose power. (before)

   ---

6. The class began the experiment. The teacher gave instructions. (after)

   ---

Section 6: Edit the Message

A student wrote this message about a community clean-up day. Rewrite it so that it has correct capitalization, punctuation, conjunctions, and sentence structure.

Original message:

we arrived at the park the grass was messy so we picked up trash and sorted the recycling although it was hot we continued working our group finished early but we helped another group

Your revised message:

Section 7: Sentence Sort

Sort the sentences by writing each sentence number in the correct group. Some sentences may contain a compound subject or compound verb but still be simple.

Sentences

1. The chef chopped vegetables and prepared the sauce.
2. The alarm rang, but nobody moved.
3. Because the road was closed, we took a different route.
4. Ava and Ben carried the boxes.
5. I studied, so I felt prepared for the quiz.
6. The lights flickered.
7. While the baby slept, the family spoke quietly.
8. The package arrived yesterday.

• Simple sentences: _____
• Compound sentences: __
• Complex sentences: ____

Section 8: Real-World Writing Mission

Imagine that you are writing a short announcement for a school club, sports team, workplace training group, or community event.

Write three sentences:

1. One simple sentence that gives a clear fact.
2. One compound sentence using a coordinating conjunction.
3. One complex sentence using a dependent-clause word such as because, when, although, before, or after.

Sentence 1: Simple

Sentence 2: Compound

Sentence 3: Complex

Optional Challenge

1. Write a sentence that includes a compound subject and a coordinating conjunction joining two independent clauses.

   ---

2. Explain why the word and does not always make a sentence compound.

   ---

3. Correct the punctuation in this sentence:

   Although the meeting ended we stayed to clean up and we organized the chairs.

   Corrected sentence: __

Answer Key

Section 1

1. Simple
2. Compound
3. Complex
4. Simple
5. Compound
6. Complex
7. Simple
8. Compound

Section 2

1. Independent clause: we went home or we listened to music at home is not applicable; correct answer: we listened to music at home. Dependent clause: Since the concert was canceled.
2. Independent clause: The class finished the project. Dependent clause: before the bell rang.
3. Independent clause 1: Elena charged her phone. Independent clause 2: she packed an extra battery. Dependent clause: none.
4. Independent clause: My friends waited. Dependent clause: while I bought the tickets.
5. Independent clause: The dog barked loudly. Dependent clause: none.

Section 3A

1. but
2. or
3. and
4. yet
5. or
6. nor
7. so

Section 3B

1. C
2. E
3. D
4. A
5. B
6. F
7. G

Section 4

Answers may vary slightly. Correct examples include:

1. The weather was cold, so we wore our coats.
2. I finished my homework, and I watched a television show.
3. You can walk to the park, or you can take the bus.
4. The team practiced every day, so it improved quickly.
5. Leo wanted to buy the game, but he had not saved enough money.
6. The dog hid under the table, for it was frightened by the thunder.

Section 5

Answers may vary slightly. Correct examples include:

1. We wore helmets when we rode our bikes.
2. I will text you when I arrive at the station.
3. The team celebrated because it won the final game.
4. We stayed indoors because the air quality was unhealthy.
5. Maya saved her work before the computer might lose power.
6. The class began the experiment after the teacher gave instructions.

A sentence is also correct when the dependent clause comes first, as long as a comma follows it. For example: Because it won the final game, the team celebrated.

Section 6

Answers may vary. One correct revision is:

We arrived at the park, and the grass was messy. We picked up trash and sorted the recycling, so the area looked cleaner. Although it was hot, we continued working. Our group finished early, but we helped another group.

Section 7

• Simple sentences: 1, 4, 6, 8
• Compound sentences: 2, 5
• Complex sentences: 3, 7

Section 8

Answers will vary. Check that:

• Sentence 1 has one independent clause.
• Sentence 2 has two independent clauses joined by a comma and a coordinating conjunction.
• Sentence 3 has one independent clause and at least one dependent clause.

Optional Challenge

1. Answers will vary. Example: Carlos and Nina planned the event, and they invited the neighborhood.
2. The word and does not always make a sentence compound because it can join two words, phrases, or verbs within one independent clause. Example: Maya and Luis practiced.
3. Although the meeting ended, we stayed to clean up, and we organized the chairs.