Chapter 1-11-2: Subordinating Conjunctions
A subordinating conjunction (also called a subordinator) introduces a dependent clause and indicates the nature of the relationship among the independent clause(s) and the dependent clause(s). These adverbs that act like conjunctions are placed at the front of the dependent clause.
Note that comma placement can be a bit tricky, depending on the situation:
Place a comma at the end of adverbial phrases when they precede the main clause. See ①, below.
Normally, writers must not place commas before subordinating conjunctions introducing dependent clauses in the middle of a sentence. See ②, below.
There are, however, a few occasions when a comma must be placed before a subordinating conjunction that introduces a dependent clause in the middle of a sentence. If the meaning of the sentence was to become unclear—namely when the sentence begins with a negative proposition—a comma is used. See ③, below.
Each of the highlighted words in the following sentences is a subordinating conjunction:
① Dependent Clauses Introduced by a Subordinating Conjunction—Dependent Clause Is Located at the Start of the Sentence
After he had learned to cook, Doug felt more autonomous.
The subordinating conjunction "after" introduces the dependent clause "After he had learned to cook."
If you prepare an essay outline, you will probably get a higher grade.
Similarly, the subordinating conjunction "if" introduces the dependent clause "If you prepare an essay outline."
② Dependent Clauses Introduced by a Subordinating Conjunction—Dependent Clause Is Located in the Middle of the Sentence
Debbie had to go to the hospital when she was involved in a collision.
The subordinating conjunction "when" introduces the dependent clause "when she was involved in a collision." Observe that there is no comma before the subordinating conjunction.
Some nutritionists believe that all types of sugar are unhealthy because they raise LDL cholesterol levels.
In this sentence, the dependent clause "because they raise LDL cholesterol levels" is introduced by the subordinating conjunction "because." Observe that there is no comma before the subordinating conjunction.
③ Dependent Clauses Introduced by a Subordinating Conjunction—Ambiguous Meanings and Negative Propositions
Few Australians eat poutine, because they have never visited Quebec.
The subordinating conjunction "because" introduces the dependent clause "because they have never visited Quebec." Without the comma, the sentence begs the question, "oh, then what is the main reason Australians eat poutine?"
Doctors don’t want to do cancer research, because the government won't give them funding.
In this sentence, the dependent clause "because the government won't give them funding" is introduced by the subordinating conjunction "because." Again, without the comma, readers are waiting for the real reason doctor's don't want to perform research. A sentence without a comma begs the question, "oh, if it's not because of the lack of funding, then what is the reason?"
Using the Word "That" as a Subordinate Conjunction
Sometimes students omit the word "that" from a sentence when it would be more natural to keep the word. What follows is some valid discussion of this topic from the reference (see resource card at the end of this section).
Theodore Bernstein lists three conditions in which we should maintain the conjunction that:
When a time element intervenes between the verb and the clause: "The boss said yesterday that production in this department was down fifty percent." (Notice the position of "yesterday.")
When the verb of the clause is long delayed: "Our annual report revealed that some losses sustained by this department in the third quarter of last year were worse than previously thought." (Notice the distance between the subject "losses" and its verb, "were.")
When a second that can clear up who said or did what: "The CEO said that Isabel's department was slacking off and that production dropped precipitously in the fourth quarter." (Did the CEO say that production dropped or was the drop a result of what he said about Isabel's department? The second that makes the sentence clear.)
The word that is used as a conjunction to connect a subordinate clause to a preceding verb. In this construction that is sometimes called the "expletive that." Indeed, the word is often omitted to good effect, but the very fact of easy omission causes some editors to take out the red pen and strike out the conjunction that wherever it appears. In the following sentences, we can happily omit the that (or keep it, depending on how the sentence sounds to us):
Isabel knew [that] she was about to be fired.
She definitely felt [that] her fellow employees hadn't supported her.
I hope [that] she doesn't blame me.
Sometimes omitting the that creates a break in the flow of a sentence, a break that can be adequately bridged with the use of a comma:
The problem is, that production in her department has dropped.
Remember, that we didn't have these problems before she started working here.
As a general rule, if the sentence feels just as good without the that, if no ambiguity results from its omission, if the sentence is more efficient or elegant without it, then we can safely omit the that."