Which sentence uses a semicolon correctly?

• A. The test was tough; many students failed.
• B. The test was tough, many students failed.
• C. The test was tough; and many students failed.
• D. The test was tough and many students failed.

Answer: (A)

Using a semicolon to connect two related independent clauses is appropriate when each part could stand as its own sentence and the ideas are closely linked. Here, both parts—“The test was tough” and “many students failed”—are complete thoughts, so joining them with a semicolon shows the relationship without adding extra words.

This is why the first option is correct: the semicolon neatly ties the two related statements without a coordinating conjunction.

The other options misapply punctuation. A comma alone creates a comma splice by joining two independent clauses without a coordinating conjunction. A semicolon followed by a coordinating conjunction is not standard usage—a semicolon should stand alone when linking two independent clauses. And omitting the comma before a coordinating conjunction when joining two independent clauses results in a run-on sentence.