Complex sentences are sentences that consist of one independent clause and at least one dependent clause. They enable the combination of main ideas with supporting or subordinate ideas.

Here are some important points to understand about complex sentences:

1. Independent Clause:

   – A complex sentence includes an independent clause, which is a group of words that can function as a complete sentence on its own.

   – The independent clause expresses a main idea or complete thought.

   – Examples:

     – “She went to the library.”

     – “He studied for the exam.”

2. Dependent Clause:

   – A complex sentence also contains one or more dependent clauses, which cannot stand alone as complete sentences.

   – Dependent clauses act as subordinate elements, providing additional information or support for the main idea expressed in the independent clause.

   – Examples:

     – “Because she needed to do research, she went to the library.”

     – “Although he was tired, he studied for the exam.”

3. Subordinating Conjunctions:

   – Dependent clauses in complex sentences are typically introduced by subordinating conjunctions.

   – Subordinating conjunctions establish the relationship between the dependent clause and the independent clause.

   – Examples:

     – Common subordinating conjunctions include “because,” “although,” “if,” “when,” “since,” “while,” “unless,” “where,” and “as.”

4. Punctuation:

   – When a dependent clause precedes the independent clause, it is usually followed by a comma.

   – However, if the dependent clause follows the independent clause and the sentence remains clear without a comma, it may be omitted.

   – Examples:

     – “She went to the library because she needed to do research.”

     – “He studied for the exam although he was tired.”

Complex sentences allow for the expression of relationships, conditions, cause and effect, and other nuanced connections between ideas. They enable the combination of main ideas with supporting thoughts in a structured and coherent manner. Understanding how to construct and use complex sentences enhances the clarity and sophistication of communication.