Complex to Compound

What’s the Difference?

Complex Sentence: Has a main clause and at least one subordinate (dependent) clause.

Compound Sentence: Has two or more independent clauses joined by coordinating conjunctions like and, but, or, so, yet, for, nor.

✅ Rule 1: Reason Clauses (Use “so” or “for”)

Explanation: If a complex sentence has a reason clause (because, as, since), change it into a compound sentence using "so" or "for".

Examples:

1.

Complex: He was tired because he worked all day.

Compound: He worked all day, so he was tired.

2.

Complex: She failed the test because she didn’t study.

Compound: She didn’t study, so she failed the test.

3.

Complex: Since he was late, he missed the bus.

Compound: He was late, so he missed the bus.

4.

Complex: I was worried because he didn’t call.

Compound: He didn’t call, so I was worried.

5.

Complex: She was ill because she got wet in the rain.

Compound: She got wet in the rain, so she was ill.

Exercise for Practice

    Instructions: Rewrite the following sentences as compound sentences using "so" or "for".

    1. He was tired because he worked late.
    2. She missed the train because she got up late.
    3. Since he was hungry, he ate all the food.
    4. The baby cried because he was sleepy.
    5. I couldn’t sleep because it was noisy outside.
    6. He was absent because he was sick.
    7. Since it rained heavily, the match was canceled.
    8. We couldn’t go out because it was too hot.
    9. They stayed home because the weather was bad.
    10. I didn’t attend the party because I had a headache.

    ✅ Rule 2: Time Clauses (Use “and”, “then”, “after that”)

    Explanation: If a complex sentence begins with a time clause (when, after, before), divide the sentence into two independent actions using "and" or "then".

    Examples:

    1.

    Complex: When he reached home, he took a shower.

    Compound: He reached home, and he took a shower.

    2.

    Complex: After she finished dinner, she watched TV.

    Compound: She finished dinner, and then she watched TV.

    3.

    Complex: Before he went out, he locked the door.

    Compound: He locked the door, and then he went out.

    4.

    Complex: When I opened the door, I saw my dog.

    Compound: I opened the door, and I saw my dog.

    5.

    Complex: After the teacher came, the students became quiet.

    Compound: The teacher came, and the students became quiet.

    Exercise for Practice

      Instructions: Rewrite the following sentences as compound sentences using "and", "then", or similar connectors.

      1. When she entered the room, everyone stood up.
      2. After I finished my homework, I watched TV.
      3. Before he went to bed, he brushed his teeth.
      4. When they saw the lion, they ran away.
      5. When the teacher arrived, the class started.
      6. After the bell rang, the students left.
      7. Before I cooked dinner, I cleaned the kitchen.
      8. When we reached the station, the train had left.
      9. After he read the letter, he became sad.
      10. Before the exam began, we checked our seats.

      ✅ Rule 3: Contrast/Concession Clauses (Use “but”)

      Explanation: Replace concessive clauses (although, though, even though) with "but" in compound sentences.

      Examples:

      1.

      Complex: Although he was tired, he kept working.

      Compound: He was tired, but he kept working.

      2.

      Complex: Even though it was raining, they played football.

      Compound: It was raining, but they played football.

      3.

      Complex: Though he is poor, he is honest.

      Compound: He is poor, but he is honest.

      4.

      Complex: Although she studied hard, she failed.

      Compound: She studied hard, but she failed.

      5.

      Complex: Even though the task was hard, he completed it.

      Compound: The task was hard, but he completed it.

      Exercise for Practice

        Instructions: Rewrite the following sentences as compound sentences using "but".

        1. Although he is old, he can walk fast.
        2. Though she was tired, she kept working.
        3. Even though it was late, they continued the meeting.
        4. Though he failed, he didn’t give up.
        5. Although I studied hard, I didn’t get an A.
        6. Though it was raining, we played cricket.
        7. Even though she was sick, she came to school.
        8. Although he apologized, she didn’t forgive him.
        9. Even though the road was slippery, the car didn’t skid.
        10. Though the food was spicy, he ate it all.

        ✅ Rule 4: Conditional Clauses (Use “or”)

        Explanation: For conditional clauses (if...then), we can change them into compound sentences using "or".

        Examples:

        1.

        Complex: If you run fast, you will catch the train.

        Compound: Run fast, or you will miss the train.

        2.

        Complex: If you don’t study, you will fail.

        Compound: Study, or you will fail.

        3.

        Complex: If you eat too much, you will fall sick.

        Compound: Eat too much, or you will fall sick.

        4.

        Complex: If you are late, you will miss the movie.

        Compound: Be late, or you will miss the movie.

        5.

        Complex: If he doesn’t work hard, he will not pass.

        Compound: He must work hard, or he will not pass.

        Exercise for Practice

          Instructions: Rewrite the following conditional sentences as compound sentences using "or".

          1. If you don’t hurry, you’ll miss the bus.
          2. If you touch that wire, you’ll get shocked.
          3. If he doesn’t listen, he will make a mistake.
          4. If they don’t leave now, they’ll be late.
          5. If you don’t water the plants, they’ll die.
          6. If she doesn’t wear a coat, she’ll catch a cold.
          7. If we don’t save money, we’ll face problems.
          8. If you don’t follow the rules, you’ll be punished.
          9. If he doesn’t stop shouting, he’ll get in trouble.
          10. If you don’t drive carefully, you’ll cause an accident.

          ✅ Rule 5: Replace Relative/Noun Clauses with Independent Clauses (Use “and”, “so”, “but”, etc.)

          Explanation: If the complex sentence has a relative clause (who, that, which) or noun clause, convert both into independent statements and join using a coordinating conjunction.

          Examples:

          1.

          Complex: I know that he is honest.

          Compound: He is honest, and I know it.

          2.

          Complex: She said that she was tired.

          Compound: She was tired, and she said so.

          3.

          Complex: The man who lives next door is a doctor.

          Compound: The man lives next door, and he is a doctor.

          4.

          Complex: He told me that he was busy.

          Compound: He was busy, and he told me.

          5.

          Complex: The girl who won the race is my sister.

          Compound: The girl won the race, and she is my sister.

          Exercise for Practice

            Instructions: Rewrite the complex sentences as compound sentences by splitting into two independent clauses.

            1. I believe that he is innocent.
            2. The girl who lives next door is my friend.
            3. He told me that he was sorry.
            4. The teacher who teaches us English is very kind.
            5. I heard that she is coming today.
            6. The boy who won the prize is my cousin.
            7. I know that you are right.
            8. The man who helped me is a policeman.
            9. She said that she didn’t know the answer.
            10. The book that I bought yesterday is very interesting.

            Exercise in Action [Grade 9 & 10]

            1. If Clause
            1. If you watch television, you can learn many things. (Compound)
            2. If a student fails in the examination, he suffers from inferiority complex. (Compound)
            3. If we read books, we can enrich our minds. (Compound)
            4. If an examinee answers all the questions, the examiner becomes glad to see that. (Compound)
            5. If we use time properly, we can be benefited. (Compound)
            6. If he makes a proper use of his time, he is sure to prosper in life. (Compound)
            7. Unless one enjoys the beauty of a moonlit night, one cannot explain it properly. (Compound)
            8. Unless you use the morning hours of life, you have to pay a heavy price afterwards. (Compound)
            9. If a student answers all the questions correctly, he will get good marks. (Compound)
            10. We can grow more crops if we can make the best use of rain. (Compound)
            11. No one can receive any reward unless he works hard. (Compound)
            12. If we throw wastage and dirt into water, we make it polluted. (Compound)
            2. When / While / After / Before
            1. When I reached there, my friend received me cordially. (Compound)
            2. One night when he was saying his prayer, a thief broke into his room. (Compound)
            3. When we read good books, we discover new worlds. (Compound)
            4. When he was eight years old, his mother died (Compound).
            5. That night, while Ruplal was sleeping, he heard a noise. (Compound)
            6. When I reached there, my friend received me cordially. (Compound)
            7. When he gets the question paper, he should read it carefully. (Compound)
            8. One night when he was saying his prayer, a thief broke into his room. (Compound)
            9. One day when a thief entered his room, he caught him. (Compound)
            10. When a man makes a journey by train, he can enjoy natural scenery. (Compound)
            11. When it is winter, the river remains calm and tranquil. (Compound) 
            12. He sat under the tree and fell asleep. (Compound)
            13. When a student gets the question paper, he should read it attentively. (Compound)
            3. Although / Though
            1. Though their weapons were ordinary, they had much courage in their mind. (Compound)
            2. Though we take utmost care, we cannot avoid death. (Compound)
            3. Though we have strict law, we are still affected by this evil. (Compound)
            4. Though we have strict law, we are still affected by this evil. (Compound) 
            5. Though it is a blessing, it has dark sides. (Compound) 
            6. Though there are laws to punish the terrorists, they are not properly applied. (Compound) 
            7. Though she was a nice little girl, she was not an ordinary child. (Compound)
            8. Though cricket is a costly game, people of all classes enjoy playing it. (Compound)
            9. There are two umpires who conduct the game. (Compound)
            10. Though there is law to punish the terrorists, it is not properly applied. (Compound)
            11. Though a healthy man is an asset to his family, an unhealthy man is a liability. (Compound)
            12. Though the moon gives us light, it does not have the light of its own. (Compound)
            13. Though we have strict law, we are still affected by this evil. (Compound)
            14. Though we have strict laws, we are still affected by this evil. (Compound)
            4. Relative Pronoun
            1. Suddenly they saw a bear which was coming towards them. (Compound)
            2. The education that he learnt from this institution played better role in his life (Compound).
            3. The man who takes bribe is next to devil. (Compound)
            4. She helped those who were helpless. (Compound)
            5. The freedom fighters who died in the Liberation War are called martyrs. (Compound)
            6. The man who takes bribe, is next to devil. (Compound) 
            7. People who are poor cannot afford to take a balanced diet. (Compound)
            5. As/Since/Because
            1. As the demand for flowers is increasing day by day, we should cultivate flower on commercial basis. (Compound)
            2. As they are our real friends, they remain with us in time of danger. (Compound)
            3. People like it as it is cheap. (Compound)
            4. As our farmers use its water for irrigation purpose, they can grow plenty of crops. (Compound)
            6. So that
            1. So, a student should be aware of studying regularly and attentively so that he can do well in the examination. (Compound)
            2. We must work hard so that we can earn money. (Compound)
            3. This quality highly motivates á man so that he can sacrifice his life for the country. (Compound)
            4. We must work hard so that we can earn money. (Compound)
            7. That
            1. We hope that Bangladesh will be free from this evil. (Compound)
            2. She believes that charity is a great virtue. (Compound)
            3. Its main source is the rain that creates streams, lakes and rivers. (Compound)