"for" or "because"?
Consider the following fill-in:
Mackenzie's clarinet squealed like a startled puppy, __ she hadn't practiced in weeks.
because
for
The presentation I'm looking at indicates "for" as the correct solution.
To me, "because" also sounds fine, but I would not use a comma after puppy in that case.
Is that essentially the reason "for" is best here, because of the way the fill-in is punctuated? Is "...puppy because..." valid also?
Your guess is right.
The exercise is trying to emphasize the difference between coordinator "for" and adverbial subordinator "because" in academic writing.
"For" is among a group of coordinating conjunctions best known by the phrase "fan boys." The group includes: F or, A nd, N or, B ut, O r, Y et, and S o.
When we combine clauses using one of the FAN BOYS, we normally put a comma after the first independent clause.
Independent clause + , + for + independent clause
On the other hand, "because" is an adverbial subordinator like although, if, while, when etc. Putting a comma between clauses depends on the position of your adverb clause. Like this:
S + V + because ... . (no comma)
Because ... + , + S + V. (with comma)
The comma should be present in either case. Both clauses that follow puppy are independent clauses. The comma reflects the separation of those distinct and complete thoughts. You could as easily write
Mackenzie's clarinet squealed like a startled puppy. She hadn't practiced in weeks.