Comma Rules — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which version correctly uses commas to set off nonessential information? "The painting (which my grandmother made) hangs in our hallway."
A) The painting which my grandmother made, hangs in our hallway.
B) The painting, which my grandmother made hangs in our hallway.
C) The painting, which my grandmother made, hangs in our hallway.
D) The painting which, my grandmother made, hangs in our hallway.
"Which my grandmother made" is a nonessential clause that adds extra detail about the painting, so commas replace the parentheses to properly set it off.
2. Which sentence does NOT need any commas?
A) The boy who won the race celebrated with his team.
B) My brother Carlos is a fast runner.
C) After practice we ate sandwiches and fruit.
D) Please sit down everyone.
"Who won the race" is an essential clause that identifies which boy is meant, so it must not be set off by commas -- removing it would change the sentence's meaning.
3. Read both sentences. Which one means something different because of the commas? A: "The students who studied passed the test." B: "The students, who studied, passed the test."
A) They mean exactly the same thing.
B) Sentence A says only some students studied; Sentence B says all students studied.
C) Sentence A is about one student; Sentence B is about many.
D) Sentence B is a compound sentence; Sentence A is simple.
Without commas (Sentence A), "who studied" is essential and limits the group to only the students who studied. With commas (Sentence B), the clause is nonessential, meaning all the students studied and all passed.
4. Which sentence correctly combines direct address, an introductory word, and a series?
A) Well Jason, please bring paper pencils, and glue.
B) Well, Jason please bring paper, pencils, and glue.
C) Well, Jason, please bring paper, pencils, and glue.
D) Well Jason please bring paper, pencils and glue.
This sentence uses three comma rules at once: a comma after the introductory word "Well," commas around the direct address "Jason," and commas separating the series of supplies.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A clause that is essential to the meaning of a sentence does not need commas around it.
An essential (restrictive) clause narrows down exactly who or what is being discussed, so removing it would change the meaning -- that is why no commas are used.
2. The word "which" usually begins a nonessential clause, while "that" begins an essential one.
"Which" signals a nonessential clause with extra detail (set off by commas), while "that" signals an essential clause the sentence cannot do without.
3. In "The park, which opened last spring, has a new playground," removing the commas and the clause still leaves a complete sentence.
If you remove "which opened last spring," the sentence "The park has a new playground" still makes complete sense, proving the clause is nonessential.
4. Adding commas around a "who" clause tells the reader the information is extra, not necessary.
Commas around a "who" clause signal that the information is bonus detail rather than necessary for identifying the person being discussed.
5. A sentence can use more than one comma rule at the same time, such as direct address and a series.
Comma rules often overlap in a single sentence; for example, "Sam, bring pens, paper, and glue" uses direct address and a series together.