Complex Sentences Worksheet

Name: ________________________________

Date: ________________________________

Score: _______/100

Quick Reference - Complex Sentences

Definition: A complex sentence has one independent clause and one (or more) dependent clauses.

Formula: Independent Clause + Dependent Clause OR Dependent Clause + Independent Clause

Key Parts:

Independent Clause: Can stand alone (has subject + predicate, complete thought)
Dependent Clause: Cannot stand alone (has subordinator + subject + predicate)
Subordinator: Makes a clause dependent (because, when, if, although, since, etc.)

Comma Rule: Dependent clause first = comma after it. Independent clause first = usually no comma (except contrast subordinators).

Section 1: Identifying Complex Sentences (20 points)

Instructions: Read each sentence. Write "C" if it's complex, "S" if it's simple, or "CP" if it's compound.

1. _____ The dog barked loudly all night.

2. _____ When the doorbell rang, the dog started barking.

3. _____ The dog barked, and the cat hid under the table.

4. _____ Because it was raining heavily, we decided to stay indoors.

5. _____ The students studied hard for their final exams.

6. _____ Although the test was difficult, most students passed it successfully.

7. _____ She went to the store, but she forgot her shopping list.

8. _____ If you finish your homework early, you can watch television tonight.

9. _____ The weather was perfect for our picnic yesterday.

10. _____ After the movie ended, we went to our favorite restaurant for dinner.

Section 2: Identifying Subordinators (15 points)

Instructions: Underline the subordinator in each complex sentence.

1. We will have a barbecue unless it rains this weekend.

2. Since you asked so nicely, I will help you with your project.

3. The children played outside while their parents prepared dinner.

4. Although she was very tired, she continued working on her assignment.

5. We need to leave early so that we don't miss the beginning of the show.

Section 3: Independent vs. Dependent Clauses (20 points)

Instructions: Label each clause as IC (Independent Clause) or DC (Dependent Clause).

1. _____ when the bell rings

2. _____ she enjoys reading mystery novels

3. _____ because the weather was perfect

4. _____ we decided to go hiking

5. _____ if you need any help

6. _____ the concert will begin at eight o'clock

7. _____ although it was expensive

8. _____ they bought the car anyway

9. _____ wherever you want to go

10. _____ I will follow you there

Section 4: Adding Commas (15 points)

Instructions: Add commas where needed. If no comma is needed, write "NC" (No Comma).

1. When the rain stopped we went outside to play.

2. She will call you after she finishes her homework.

3. Because the library was closed we went to the bookstore instead.

4. We enjoyed the party although it was very crowded.

5. If you study hard you will pass the test with flying colors.

Section 5: Completing Sentence Fragments (15 points)

Instructions: Complete each fragment by adding an independent clause.

1. Because the weather was beautiful today

2. When the teacher entered the classroom

3. Although she had never been there before

4. If you want to improve your grades

5. Since we have extra time this afternoon

Section 6: Building Complex Sentences (15 points)

Instructions: Combine each pair of simple sentences into one complex sentence using an appropriate subordinator. Use proper punctuation.

1. The concert was cancelled. It started raining heavily.

2. She practices piano every day. She wants to become a professional musician.

3. The movie was three hours long. We enjoyed every minute of it.

4. You finish your vegetables. You can have dessert.

5. The phone rang. I was taking a shower.

Common Subordinators by Function

Time: when, while, after, before, until, since, as soon as

Reason/Cause: because, since, as

Contrast: although, though, even though, while, whereas

Condition: if, unless, provided that, as long as

Place: where, wherever

Purpose: so that, in order that

Answer Key

Section 1: Identifying Complex Sentences

1. S (Simple) | 2. C (Complex) | 3. CP (Compound) | 4. C (Complex) | 5. S (Simple)

6. C (Complex) | 7. CP (Compound) | 8. C (Complex) | 9. S (Simple) | 10. C (Complex)

Section 2: Identifying Subordinators

1. unless | 2. Since | 3. while | 4. Although | 5. so that

Section 3: Independent vs. Dependent Clauses

1. DC | 2. IC | 3. DC | 4. IC | 5. DC | 6. IC | 7. DC | 8. IC | 9. DC | 10. IC

Section 4: Adding Commas

1. When the rain stopped, we went outside to play.

2. NC (No comma needed)

3. Because the library was closed, we went to the bookstore instead.

4. We enjoyed the party, although it was very crowded.

5. If you study hard, you will pass the test with flying colors.

Section 5: Completing Sentence Fragments (Sample Answers)

1. Because the weather was beautiful today, we decided to have a picnic in the park.

2. When the teacher entered the classroom, all the students became quiet.

3. Although she had never been there before, she found the museum easily.

4. If you want to improve your grades, you should study more regularly.

5. Since we have extra time this afternoon, let's visit the art gallery.

Section 6: Building Complex Sentences (Sample Answers)

1. The concert was cancelled because it started raining heavily.

2. She practices piano every day so that she can become a professional musician.

3. Although the movie was three hours long, we enjoyed every minute of it.

4. If you finish your vegetables, you can have dessert.

5. The phone rang while I was taking a shower.

Grading Scale

A: 90-100 points | B: 80-89 points | C: 70-79 points | D: 60-69 points | F: Below 60 points