What Is a Subordinating Conjunction?

A subordinating conjunction is a word or phrase that links a dependent clause to an independent clause. This word or phrase indicates that a clause has informative value to add to the sentence’s main idea, signaling a cause-and-effect relationship or a shift in time and place between the two clauses.

Sound complicated? Let’s break it down.

A dependent clause, also known as a subordinate clause, is a clause with two specific qualities. Firstly, it does not express a complete unit of thought on its own; it cannot stand as its own sentence. Secondly, it depends upon an independent clause—one that can stand on its own as a complete sentence—to form a complete idea. If independent and dependent clauses could be likened to Batman and Robin, the dependent, or subordinate clause would be Robin, Batman’s assistant. The independent, main clause would be Batman, his superhero boss.

Subordinating Conjunctions Showing Cause and Effect

The subordinating conjunction that is simplest to explain is because. Because is a conjunction with just one purpose: to show a cause-and-effect relationship between a subordinate clause and a main clause. On its own, a clause beginning with because is incomplete.

Example :                Because he wouldn’t wear a seat belt.

We have the sense that there is something missing here. Let’s add an independent clause so this statement has something to lean on.

Example :             Robin wasn’t allowed in the Batmobile any longer.

Now we will combine the two in a complex sentence.

Example  :            Robin wasn’t allowed in the Batmobile any longer because he wouldn’t wear a seatbelt.

In this sentence, “Robin wasn’t allowed in the Batmobile any longer” is an independent clause. It could stand on its own as a complete sentence. A clause that shows a causal relationship such as “because he wouldn’t wear a seatbelt” (answering the question “Why?” or “For what purpose?” is often referred to as a clause of purpose.

Other subordinating conjunctions that can show cause-and-effect relationships and function in the same way are for, as, since, therefore, hence, as a result, consequently, though, due to, provided that, because of, unless, as a result of, and so/so that.

Example :            Batman required strict compliance with seat belt rules, hence Robin was not allowed to ride in the Batmobile.

Example :             Since Robin refused to wear his seat belt, Batman has banned him from the Batmobile.

Subordinating Conjunctions Signaling Relationships of Time or Place

Another function of subordinating conjunctions is to show a relationship between two clauses involving a transition of time or place. Some examples of such subordinating conjunctions are once, while, when, whenever, where, wherever, before, and after.

Example :          Once Batman learned that Robin had not been wearing his seatbelt, he took away his keys to the Batmobile.

Example :          Robin looked regretfully at the Batmobile whenever he passed it in the Batcave.

Example :          After Batman was done working for the night, Robin took a secret ride in the Batmobile.

Example :          Before Robin gets his job in the Batcave back, he must promise to stop playing with the Batmobile.

Comma Placement and Subordinating Conjunctions

Subordinating conjunctions that fall in the middle of a sentence are generally not preceded by a comma. This is the opposite of what is done with coordinating conjunctions, or words that join two independent clauses (for, and, nor, but, or, yet, and sometimes so).

When a subordinate clause begins a sentence, however, the whole clause (but not the subordinating conjunction itself) is followed by a comma.

Incorrect :          Whenever, Batman was away, Robin drove the Batmobile.

Correct :             Whenever Batman was away, Robin drove the Batmobile.

Incorrect :           Robin drove the Batmobile, whenever Batman was away.

Correct :              Robin drove the Batmobile whenever Batman was away.

A Handy List of Subordinating Conjunctions :

After / although / as / as if / as long as / as much as / as soon as / as though / because / before / by the time / even if / even though / if / in order that / in case / in the event that / lest / now that / once / only / only if / provided that / since / so / supposing / that / than / though / till / unless/ until / when / whenever / where / whereas / wherever / whether or not / while