Identify type of sentence: “I know why people are making noise.”

The sentence "I know why people are making noise" is a complex sentence. A complex sentence is characterized by having one independent clause and at least one dependent clause. In this sentence, "I know" is the independent clause, which can stand alone as a complete thought. The phrase "why people are making noise" is a dependent noun clause that functions as the direct object of the verb "know." It cannot stand alone as a complete sentence.

• A simple sentence has only one independent clause.
• A compound sentence has two or more independent clauses.
• A compound-complex sentence has two or more independent clauses and at least one dependent clause.

Understanding clause structure is crucial for identifying sentence types.