Subordination in Complex Sentences

September 09, 2025

Posted by STLCC in Tutoring Resources 

Basic rules

If you’ve ever reported to a boss or supervisor, you already understand subordination. As a worker, you support your boss. In the same way, one idea in a complex sentence supports the other. The more important idea goes into an independent clause (which can stand alone) while the supporting idea goes into a dependent clause (which cannot stand alone). This pattern (independent + dependent clauses) creates a complex sentence.

These conjunctions frequently begin dependent clauses:

• after
• although
• as
• as if
• as long as
• as though
• because
• before
• how
• if
• once
• in order that
• since
• so that
• provided
• than
• though
• unless
• until
• when
• whenever
• where
• wherever
• while

Tired of short, choppy and monotonous sentences in your writing? Use more complex sentences in which the independent (main) and dependent (subordinate) clauses are linked by a logical conjunction. This technique makes your writing more sophisticated, especially if you almost always connect sentences with the FANBOYS words (for, and, nor, but, or, yet, so).

How to punctuate complex sentences

If the dependent clause begins your sentence, use a comma after it. Read these examples. (The dependent clause is italicized.)

• Because they were so busy, they skipped lunch.
• Whenever he hears that special song, he thinks of his old girlfriend.
• Once everybody boards, the ship can begin its three-hour cruise.

Important point: These examples follow the rule to use a comma when the dependent clause begins the sentence.

Do not use a comma if the dependent clause ends your sentence except in cases of extreme contrast. Read these examples. (The dependent clause is italicized.)

• A mouse ate the cheese while our lazy cat slept.
• I can help you with your paper provided you bring me the rough draft.
• Samantha was the most even-tempered person we know, although none of us can forget her meltdown in ’09.

Important point: These examples follow the rule to omit the comma when the dependent clause ends the sentence.

Learn more about "Subordination vs. coordination."