What Is A Complex Sentence?

A complex sentence is one independent clause and at least one dependent clause joined by a subordinating conjunction. Complex sentences are one of the four basic types of sentences in the English language.

Complex sentences require at least three parts:

  1. Independent clause
  2. Subordinating conjunction
  3. Dependent clause or clauses

Complex Sentence Definition

Independent Clauses

In writing, entire ideas expressed using a noun and verb (a subject and predicate) create independent clauses. Independent clauses can be complete sentences on their own.

Here is a wonderful succession of simple sentences (each an independent clause) from Franz Kafka’s Metamorphosis:

I’m in the midst of getting out of bed. Just have patience for a short moment! Things are not going so well as I thought. But things are all right.

Things certainly are not going well for Kafka’s protagonist because Gregor Samsa has turned into a “monstrous verminous bug.”

Dependent Clauses

Dependent clauses, also called the subordinate clause, have a noun and verb but fail to express a complete thought. In these sentences penned by Kafka, the dependent clauses are underlined:

  • No matter how hard he threw himself onto his right side, he always rolled again onto his back.
  • If I were to try that with my boss, I’d be thrown out on the spot.
  • Because the lodgers sometimes also took their evening meal at home in the common living room, the door to the living room stayed shut on many evenings.

These examples have nouns and verbs, but they are not a complete thought. If all Kafka had written was, “No matter how hard he threw himself onto his right side,” you would have no idea what was happening to Gregor Samsa.

If left by themselves, dependent clauses a sentence fragment.

Several dependent clauses can spin-out from the independent clause, leading to very long sentences.

Complex Sentence Examples

You can write complex sentences in a few different ways. Here are some rules to help you construct complex sentences:

  • Dependent Clause + Independent Clause (comma splits the clause)
  • Independent Clause + Dependent Clause (comma usually does not split the clause)

Complex Sentence Structure

Here are four examples of complex sentences where the dependent clause comes first:

  1. When I was a child, I love playing baseball.
  2. As you may know, writing with correct English grammar can be challenging.
  3. Since summer is around the corner, we all bought new bathing suits.
  4. Because she was late for work, she was frustrated.

Here are those same four examples with the independent clause first:

  1. I enjoyed playing baseball when I was a child.
  2. Writing with correct English grammar can be challenging, as you may know.
  3. We all bought new bathing suits since summer is around the corner.
  4. She was frustrated because she was late for work.
Notice our comma usage. One of our examples where the independent clause comes first required a comma before the subordinating conjunction.

Complex Sentence Conjunctions

In complex sentences, dependent clauses are linked to independent clauses with subordinating conjunctions. These are words that couple the two clauses together.

In many cases, these subordinating words come after the independent clause and just before the dependent clause like here:

But that would be extremely embarrassing and suspicious, because during his five years’ service Gregor hadn’t been sick even once.

Many words operate as subordinating conjunctions. They often cluster around concepts, like comparisons, time, reason, and conditions.

List Of Subordinators For Complex Sentences
Concept Conjunction
Adding information about a person who, whose, whoever, whom, whomever
Adding information about a thing which, at
Condition if, unless, as long as
Contrast than, rather than, as much as, although, though, even though, while, whereas
Introducing reported information that, whether, how
Manner as
Place where
Purpose so that, only if, even if, provided that
Reason because, since, as
Time now that, when, whenever, as soon as, while, as, once, until, after, before, by the time

These are just some common subordinating conjunctions. This list is not exhaustive. Dozens and dozens of words and phrases can serve to join the dependent clause to the independent clause.

Complex Sentence Subordinating Conjunctions

Remember, the subordinating conjunction can be anywhere in the sentence, though it almost always precedes the dependent clause.

Complex Sentences Clauses

In addition to subordinating conjunctions, complex sentences can use three types of clauses, called subordinating clauses:

  1. Adjective clause
  2. Noun clause
  3. Adverb clause

These take the place of adjectives, nouns, and adverbs.

Complex Sentences Subordinating Clauses

Examples of adjective clauses working as dependent clauses in complex sentences might be:

  • The thief who had taken the pony was found guilty by the jury.
  • The apartment that felt drafty even in spring needed remodeling.

Examples of noun clauses working as dependent clauses in complex sentences might be:

  • Whoever added the eraser to a pencil was very clever.
  • While on vacation, we can do whatever we like.

Examples of adverb clauses working as dependent clauses in complex sentences might be:

  • Although we played well, we lost the baseball game.
  • Whether we liked it or not, we lost by many runs.

Issues Writing Complex Sentences

Kafka was a master of language; he had unwritten permission (from generations of readers) to violate all the “rules” of writing. You do not. When crafting your sentences, be careful to avoid traps with complex sentences.

  1. Losing sight of your main idea – Using punctuation, adding subordinating conjunctions, and tacking on streams of dependent clauses, you fall in love with making ever-longer sentences that crush the soul of your intent.
  2. Writing run-on sentences – Forgetting to use either punctuation or subordinating conjunctions, you run the dependent clause right into the independent clause.
  3. Confusing compound sentences with complex sentences – Compound sentences use one of the seven coordinating conjunctions (for, and, nor, but, or, yet, so; FANBOYS) to link independent clauses, while complex sentences use one of many (seemingly countless!) subordinating conjunctions to connect the independent clause with the dependent clause.

Four Types Of Sentences

In addition to complex sentences, there are three other types of sentences. Here are the four basic sentence types you have in the English language.

  1. Simple sentence – One independent clause (one subject, one predicate)
  2. Complex sentence – One independent clause, subordinating conjunction, and one or more dependent clauses
  3. Compound sentence – Two or more independent clauses, often linked by coordinating conjunctions (FANBOYS)
  4. Compound-complex sentence – Two or more independent clauses and at least one dependent clause

The different types of sentences have their own sentence structure. Learn more about the types of sentences structure.

What you learned:

After working your way through this lesson and video, you have learned:

  • The definition of a complex sentence
  • A complex sentence uses subordinating conjunctions to join an independent clause with a dependent clause.
  • Many subordinating conjunctions serve to signal the dependent clause to be less important than the independent clause.
  • Subordinating clauses can operate as nouns, adjectives, or adverbs to signal the dependent clause's start.
  • No rule dictates the order of subordinating conjunction (or clause), the independent clause, and the dependent clause, although the subordinating conjunction or clause nearly always precedes the dependent clause.
Instructor: Malcolm M.
Malcolm has a Master's Degree in education and holds four teaching certificates. He has been a public school teacher for 27 years, including 15 years as a mathematics teacher.

20+ English Tutors in Ashburn, VA

Get better grades with tutoring from top-rated private tutors. Local and online.


View Tutors
Tutors online
Ashburn, VA

20+ English Tutors are available to help

Get better grades with tutoring from top-rated professional tutors. 1-to-1 tailored lessons, flexible scheduling. Get help fast. Want to see the tutors near you?