Comma Rules — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Which sentence uses commas correctly?
A) After we ate lunch, we walked to the park, and played basketball.
B) After we ate lunch, we walked to the park and played basketball.
C) After we ate lunch we walked to the park, and played basketball.
D) After, we ate lunch we walked to the park and played basketball.
Comma after the introductory clause 'After we ate lunch.' Then 'walked to the park and played basketball' are compound verbs (no comma needed before 'and' with compound verbs).
2. Where should commas be placed in this sentence? "My neighbor Dr. Torres who is a dentist fixed my brother's tooth."
A) My neighbor, Dr. Torres who is a dentist, fixed my brother's tooth.
B) My neighbor Dr. Torres, who is a dentist fixed my brother's tooth.
C) My neighbor, Dr. Torres, who is a dentist, fixed my brother's tooth.
D) My neighbor Dr. Torres who is a dentist fixed, my brother's tooth.
Both 'Dr. Torres' (appositive) and 'who is a dentist' (non-essential relative clause) require commas around them.
3. Which sentence correctly uses a comma with a FANBOYS conjunction?
A) The dog barked loudly, and scared the mail carrier.
B) The dog barked loudly and, scared the mail carrier.
C) The dog barked loudly, and the mail carrier jumped back.
D) The dog barked, loudly and the mail carrier jumped back.
A comma before 'and' is correct when it joins two independent clauses ('The dog barked loudly' and 'the mail carrier jumped back').
4. Which sentence does NOT need a comma?
A) Although it was cold we still played outside.
B) My sister and I went to the store.
C) Mr. Kim our science teacher showed us an experiment.
D) I packed apples grapes and crackers for lunch.
'My sister and I went to the store' has no introductory element, compound sentence, series, or appositive — no comma needed.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A comma is needed after an introductory clause such as "Because it was raining."
An introductory dependent clause (starting with 'because,' 'although,' 'when,' etc.) is followed by a comma.
2. Two short independent clauses joined by "and" may not need a comma if they are both very short.
Very short compound sentences (e.g., 'I came and I left') may omit the comma before 'and.'
3. In a sentence with multiple appositives, each one must be set off by its own pair of commas.
Each appositive must be surrounded by commas to clearly separate it from the rest of the sentence.
4. A comma splice happens when two complete sentences are joined by only a comma and no conjunction.
A comma splice incorrectly joins two independent clauses with only a comma.
5. The comma before "and" in a compound sentence goes before the conjunction, not after it.
The comma always precedes the coordinating conjunction: 'I studied, and I passed.'