A punctuation question with a joining word tests how to link the words on each side. Split at the join and test both sides: can each side stand alone? A full sentence needs a subject, who or what it's about, and a verb telling what happens, with no word making it depend on another sentence. Use a comma before a joining word between full sentences, but not between verbs sharing a subject. Don't add punctuation only because you'd pause there.
Hints
- Hint 1
Focus on the words about the café and the line of customers. Find who or what each part is about and what it does.
- Hint 2
Set the joining word aside and test each part as a separate sentence. Does either part need words from the other part to be complete?
Step-by-step
Test both sides of the join
Step 1Test the opening words
Split after day to see what the punctuation must join, setting yet aside for the test. Can the first side stand alone? The café had just opened tells us who the words are about and what happened. That makes the first side a full sentence.
- Step 2
Test the words about the line
Now test the line of customers already stretched around the corner. Does this part say who did what without borrowing words from the first part? The line is what the sentence is about, and stretched says what it did. The second side can stand alone too, so we're joining two full sentences.
- Step 3
Place the comma
A joining word between two full sentences needs a comma before it, not after it. The versions with day yet and day yet, lack the comma before yet, while day, yet, adds an unneeded comma after it. The version with day, yet puts the comma before yet and lets it introduce the next sentence without an interruption. Choice C.