How to write a complex essay. Remember that a complex sentence is just more than one simple sentence put together to make one sentence. We therefore need to learn and become confident using the various grammatical structures that allow us to do that. Below are a few ways we can link ideas together in a sentence. To make a complex sentence we normally should have two things- a dependent clause and an independent clause. A clause is a group of words with both a subject and a verb. An example of a dependent clauses is ‘….because the weather was cold.’ This is a dependent clause because it has a subject and a verb but it doesn’t make any sense on its own. To make sense we need to add an independent clause. As the name suggests, an independent clause can make sense on its own. For example, ‘I wore a warm coat.’ If we combine these two clauses we get a complex sentence- ‘I wore a warm coat because the weather was cold.’