Complex sentences are those sentences that have more than one subject and one verb. Combining simple sentences to make one complex sentence is considered as a very important exercise to improve writing abilities. Children and beginners usually tend to make mistakes, spoken as well as written when it comes to complex sentences. 

A complex sentence is formed by adding one or more dependent clauses to the independent clause using conjunction and/or relative pronoun.

Clause: A group of words that contain a verb. 

Parts of a complex sentence:

Dependent clause: A dependent clause is a group of words that consists of a subject and verb. 

Independent clause: An independent clause is a clause that can stand by itself and form a complete sentence.

Subordinate conjugations: These are words that connect the independent and the dependent clause. 

Compound vs Complex sentence:

It is easy to mix up these two terms but grammatically they are different. 

A compound sentence is two independent clauses connecting with coordinating conjugation (for, and, nor, but, or, yet, so).

Coordinating conjugation: A coordinating conjugation is a word that joins two elements of equal grammatical rank like two nouns, two verbs, two adjectives, two phrases and two independent clauses. 

Examples of complex sentences:

Let’s start with an independent clause.

• Jacob sipped on his coffee.

This is an independent clause because it is a complete sentence. It has a subject and a verb.

Let’s see one with a dependent clause.

• While Jacob sipped on his coffee

This sentence might have a subject and a verb but it still does not complete the sentence. It still needs more information. 

Now, to connect a dependent and an independent clause, you need a subordinate conjugation. For example words like after, while or since to complete a sentence. 

Complex sentences are a wonderful addition to your writing practice. They tend to add a fuller description and allow you to add a little more detail to your writing. 

Always be cautious about the comma you place while writing such sentences. Sentences where the dependent clause is written first, you will have to separate the clauses with a comma. 

Learn to read your work out loud so that you know where to add a comma. Addition of comma can be done to sentences wherever you feel there should be a pause.