Sentences can be found in four types of structures. These structures include: (1) the simple sentence structure, (2) the compound sentence structure, (3) the complex sentence structure and (4) the compound-complex sentence structure.
The simple sentence is made up of three basic parts that include a subject (or clause), a verb and an object.
Example: Katherine bought a ticket.
“Katherine” is the subject of the sentence while “bought” is the verb. Finally, the “ticket” is the object.
The compound sentence is when you have two or more independent subjects (or clauses) that are usually joined or linked by a conjunction.
Example: Daddy played golf while Mommy played cards.
“Daddy” and “Mommy” are two independent subjects and they are linked by the conjunction “while”. You will also note that “Daddy played golf” and “Mommy played cards” can each stand on their own as simple sentence structures.
The complex sentence is when you link an independent clause with a dependent clause. An independent clause is the part of a sentence that could stand alone as a complete sentence. A dependant clause is the part of the sentence that if used alone, would not be a complete sentence.
Example: Tracy sat down when a seat opened.
Let’s break this sentence down. “Tracy sat down” is an independent clause because if removed from the complete sentence above, it would remain a sentence itself, i.e., “Tracy sat down.” On the other hand, “when a seat opened” is a dependent clause. When removed from the complete sentence above, it cannot stand on its own as an independent, complete sentence. This makes this part of the sentence dependent upon “Tracy sat down”.
The compound-complex sentence is a combination of the compound sentence having two or more independent subjects (or clauses) and the complex sentence where you have at least one independent clause and one dependent clause.
Example: Jackson went to the store and bought a loaf of bread but his grandmother had asked him to pick up some milk which he forgot.
“Jackson” and “his grandmother” are two independent subjects and they are linked by the conjunction “but”. “Jackson went to the store and bought a loaf of bread but his grandmother had asked him to pick up some milk” is an independent clause. It can stand alone as a complete sentence. However, “which he forgot” is the part of the sentence that cannot stand alone as a complete sentence. It is dependent upon “Jackson went to the store and bought a loaf of bread but his grandmother had asked him to pick up some milk.” So, in this sentence we then have all of the elements to make this a compound-complex sentence.