Answer: The main idea is the point of the paragraph. It is the most important thought about the topic. To figure out the main idea, ask yourself this question: What is being said about the person, thing, or idea (the topic)? The author can locate the main idea in different places within a paragraph. The main idea is usually a sentence, and it is usually the first sentence. The writer then uses the rest of the paragraph to support the main idea.
Answer: The difference between a compound sentence and complex sentence is that a compound sentence has two independent clauses and a complex sentence has one independent clause and one dependent clause
You could use both as long as you use them correctly
