Comma vs. Semicolon in Compound Sentences: Exercise

Brought to you by The Purdue University Online Writing Lab.

Each of the following sentences needs either a comma or a semicolon. Choose the correct punctuation mark from the drop down list. Click on the button at the bottom of the page to check your answers.

1. Many companies make sugar-free soft drinks, which are flavored by synthetic chemicals , ; the drinks usually contain only one or two calories per serving.

2. Mr. Leyland played the viola professionally for many years , ; and he now conducts a community orchestra.

3. The crab grass was flourishing , ; but the rest of the lawn, unfortunately, was dying.

4. The hill was covered with wildflowers , ; it was a beautiful sight.

5. As I turned around, I heard a loud thump , ; for the cat had upset the goldfish bowl.

6. The artist preferred to paint in oils , ; he did not like watercolors.

7. The house was clean, the table set, and the porch light on , ; everything was ready for the guests' arrival.

8. He looked carefully in the underbrush , ; but he failed to notice the pair of green eyes staring at him.

9. The foundations of the house had been poured , ; but, to his disappointment, nothing else had been done because of the carpenters' strike.

10. The computer could perform millions of operations in a split second , ; however, it could not think spontaneously.

11. I thought registration day would be tiring , ; but I didn't know I'd have to stand in so many lines.

12. The dog, growling and snarling, snapped at me , ; I was so frightened that I ran.

13. The snowstorm dumped twelve inches of snow on the interstate , ; subsequently, the state police closed the road.

14. Professors are supposed to be absent-minded , ; and I've seen plenty of evidence to support that claim since I've been in college.

15. The suspect said that he had never met the victim , ; however, the detective knew that he was lying.

16. In the first place, it was snowing too hard to see the road , ; in the second place, we had no chains.

17. I have read Soul on Ice , ; but I have not read The Invisible Man.

18. San Francisco is my favorite city , ; in fact, I plan to spend two weeks there this summer.

19. The quarterback made a brilliant pass , ; and the end crossed the goal line for the winning touchdown.

20. Large supermarkets fascinate me , ; I can find everything from frozen chow mein to soybean flour in one place.

21. Ron and Mike were both in English class this morning , ; they gave an interesting presentation on their research.

22. The obstacles are not insurmountable , ; but they are real and formidable.

23. Riding a bicycle is excellent exercise , ; I ride mine every day.

24. I am not interested in a trip to Asia this year , ; however, I would like to go to Europe.

25. Not all highly educated people enjoy traveling , ; but many world travelers are particularly well educated.