Complex Sentences

A complex sentence is a sentence structure used to show unequal relationships between ideas. It helps you state a primary thought and add background details, reasons, or conditions.

1. Grammatical Definition

A complex sentence contains exactly one independent clause and at least one dependent clause.

  • Independent Clause: Expresses the main action or complete thought.
  • Dependent Clause: Begins with a subordinating conjunction or a relative pronoun and cannot stand alone.

2. Using Subordinating Conjunctions

Subordinating conjunctions link a dependent clause to an independent clause. Common subordinating conjunctions include because, although, since, if, when, while, unless, until, before, after.

The Comma Rule:

The placement of the comma depends entirely on the order of the clauses:

  • Rule A: If the dependent clause comes first, you must place a comma between the clauses.
    • Structure: Subordinating Conjunction + Dependent Clause, + Independent Clause
    • Example: Because it was raining, we stayed indoors.
  • Rule B: If the independent clause comes first, you do not use a comma.
    • Structure: Independent Clause + Subordinating Conjunction + Dependent Clause
    • Example: We stayed indoors because it was raining.

3. Using Relative Pronouns (Relative Clauses)

A complex sentence can also be formed using a relative clause (adjective clause) introduced by relative pronouns like who, whom, whose, which, that.

  • Example: The teacher [who taught us English] was very kind.
    • Independent: The teacher was very kind.
    • Dependent: who taught us English (modifies the noun teacher).
  • Example: I bought a laptop [that was on sale].

4. Complex Sentences in Writing

Complex sentences are essential for explaining:

  • Cause & Effect: _ Since you are here, we can start._
  • Time/Sequence: _ After I finished dinner, I walked the dog._
  • Condition: _ If it snows tomorrow, school will be closed._
  • Contrast/Concession: _ Although she was tired, she kept working._

Complete Sentence Examples

Here are more examples of complex sentences:

  1. If you study hard, you will pass the exam.
  2. I will call you when I arrive at the station.
  3. Although the book was long, she finished reading it in one day.
  4. We went to the beach while the sun was shining.
  5. The house [which has a red roof] belongs to my uncle.
  6. She didn’t attend the meeting because she was feeling sick.
  7. Unless you hurry, you will miss the bus.
  8. The woman [who won the competition] is a doctor.