writing test

What follows are the (mostly) unpunctuated, uncapitalized elements of a compound-complex sentence (i.e., a sentence with at least two independent clauses and at least one dependent clause). Rewrite the following text as a single sentence with correct punctuation and capitalization. More than one correct answer is possible.

we can dance
if we want to
we can leave
your friends behind
'cause your friends
don't dance and
if they don't dance
well they're
no friends of mine

(with special thanks to the Men Without Hats)

Highlight the space between the brackets to see two possible ways to write the sentence in question, plus an explanation:

[1. We can dance if we want to; we can leave your friends behind because your friends don't dance, and if they don't dance, well, they're no friends of mine.
2. We can dance if we want to; we can leave your friends behind—because your friends don't dance, and if they don't dance, well, they're no friends of mine.
You don't normally use a comma with a subordinating conjunction like "if" or "because" if the given subordinate clause isn't at the head of the sentence. Examples:

• If you do that again, I'll kill you. (subordinate clause at the head, therefore comma)
• I'll kill you if you do that again. (subordinate clause not at the head, therefore no comma)

The justification for the em dash in the second "dance" sentence is that many people will read the line as having a dramatic pause, and an em dash fulfills that function nicely while also avoiding the "no comma before 'because'" issue. The justification for the comma before the "and" is a bit complex. Normally, a comma-and construction separates two independent clauses the way a semicolon does, but in this case, the comma-and actually introduces an entire complex sentence. In such a case, the same rule applies, i.e., treat the situation as if the comma-and were merely introducing a single independent clause. Why? Because, as is the case with an independent clause, the complex sentence is expressing a complete thought.]