subordinating conjunctions

The word conjunction comes from a Latin root meaning “join.” In grammar, a conjunction is a joining word.

Definition

A subordinating conjunction is a joining word that connects two clauses of unequal value. (A clause is a word group containing a subject and a verb.) The clause that begins with the subordinating conjunction is called a subordinate (or dependent) clause. It is less important than the other clause, which is called the main (or independent) clause.

Example

For example, consider these two clauses:

• Audrey lit up a cigarette.
• Henry grabbed the fire extinguisher.

Although they are grammatically equal, these two independent clauses don’t express equally important ideas. The second clause seems to be the main idea, and the first clause seems merely secondary.

We can join these clauses of unequal value into a single sentence by placing the subordinating conjunction as at the beginning of the less important idea:

• As Audrey lit up a cigarette, Henry grabbed the fire extinguisher.

The first clause is now a subordinate, or dependent, clause. It is no longer grammatically equal to the main clause because it cannot stand alone. For that reason, it must be joined to the main clause so that the two clauses form a single sentence. (Left by itself, a subordinate clause is a fragment, a common type of sentence error.)

Common subordinating conjunctions

Some of the most common subordinating conjunctions are shown below, grouped into categories according to the relationships they express. (In the examples, the subordinate clauses are in square brackets, and the conjunctions are in italics.)

Cause: as, because, since

• [Because Heinrich’s joints were creaking], he oiled them.

Comparison: as, than

• Lacey won’t win the contest by eating perogies faster [than Hank can count].

Condition: if, provided (that), unless

• [If you plot revenge], be prepared to dig two graves. (Chinese proverb)

Concession: although, (even) though, whereas, while

• [Although Gordon watered his cactus regularly], it didn’t thrive.

Manner: as, as if, as though

• Sylvester looked pleased, [as if he had swallowed a canary].

Place: where, wherever

• [Wherever the mice laugh at the cat], there you will find a hole. (Portuguese proverb)

Purpose: in order that, so that

• Jessica is learning to moonwalk [so that she can become an astronaut].

Time: after, as, before, once, since, till, until, when, while

• Greta’s letters have been less regular [since she moved to Come-by-Chance].

Other: that (used to introduce a clause that functions as a noun)

• After her offer to lend him a toque, Eric suspected [that Lauren didn’t like his new haircut].

Subordinating conjunctions vs. prepositions

Some subordinating conjunctions (especially those expressing time) can also act as prepositions. As prepositions, they introduce a phrase without a subject and verb:

• after work
• before closing time
• since our arrival
• until lunchtime

As conjunctions, they introduce a clause containing a subject and verb:

• after you get off work
• before the bank closes
• since we arrived
• until lunch is served