How should commas be used when connecting two complete sentences?

• A. A comma must be placed before the conjunction when joining two complete sentences.
• B. A semicolon should be used before the conjunction.
• C. No punctuation is needed when joining two sentences.
• D. A colon should be used before the conjunction.

Answer: (A)

When you connect two independent sentences with a coordinating conjunction (and, but, or, nor, for, so, yet), you place a comma before the conjunction. This comma signals the pause that ties two complete thoughts together and clarifies the relationship between them, whether it’s addition, contrast, choice, cause, or result. For example: “She studied hard, and she passed the exam.” The comma helps readers see that two separate statements are now one compound idea.

Using a semicolon before the conjunction isn’t correct because a semicolon typically joins two independent clauses without a coordinating conjunction. No punctuation is needed between two independent clauses would create a run-on sentence, making the ideas harder to parse. A colon before the conjunction isn’t appropriate here either; a colon introduces explanation, elaboration, or lists, not a simple join with a conjunction.

So the standard, correct approach is to place a comma before the coordinating conjunction when linking two complete sentences.