Which sentence demonstrates correct comma usage when joining two independent clauses with a dependent clause in the middle?

Which sentence demonstrates correct comma usage when joining two independent clauses with a dependent clause in the middle?

• A. I tried backing out of a parking space but because my emergency brake was still on, I didn't move.
• B. I tried backing out of a parking space, but because my emergency brake was still on, I didn't move.
• C. I tried backing out of a parking space, but because my emergency brake was still on I didn't move.
• D. I tried backing out of a parking space but, because my emergency brake was still on, I didn't move.

Answer: (B)

When a dependent clause interrupts two independent clauses, you set off the middle part with a comma on both sides and place a comma before the coordinating conjunction that links the two independent clauses. In this sentence, the independent clause before the interruption is “I tried backing out of a parking space,” and the independent clause after the interruption is “I didn’t move.” The middle dependent clause is “because my emergency brake was still on.” So it should be punctuated as: I tried backing out of a parking space, but because my emergency brake was still on, I didn't move. This is why it’s correct: there are commas both before the conjunction and after the interrupting dependent clause, making the structure clear and readable. The other options fail because: - The lack of a comma before the conjunction makes the two independent clauses run together awkwardly. - The missing comma after the middle dependent clause leaves the interrupter not properly separated. - The placement in the last option has an incorrect comma after the conjunction, which disrupts the natural pause of the sentence.

When a dependent clause interrupts two independent clauses, you set off the middle part with a comma on both sides and place a comma before the coordinating conjunction that links the two independent clauses. In this sentence, the independent clause before the interruption is “I tried backing out of a parking space,” and the independent clause after the interruption is “I didn’t move.” The middle dependent clause is “because my emergency brake was still on.” So it should be punctuated as: I tried backing out of a parking space, but because my emergency brake was still on, I didn't move.

This is why it’s correct: there are commas both before the conjunction and after the interrupting dependent clause, making the structure clear and readable.

The other options fail because:

• The lack of a comma before the conjunction makes the two independent clauses run together awkwardly.

• The missing comma after the middle dependent clause leaves the interrupter not properly separated.

• The placement in the last option has an incorrect comma after the conjunction, which disrupts the natural pause of the sentence.