In many ways, a complex-compound sentence is just as complicated as its name seems to suggest. Complex sentences are those that contain an independent clause and one or more dependent clauses. A compound sentence is one that has two or more independent clauses, which are typically joined together by a conjunction such as "and." As the name indicates, a complex-compound sentence combines both of these elements to create a single sentence with two or more independent clauses and at least one dependent clause.
To fully understand the structure of a complex-compound sentence, it is typically easiest to consider more basic forms first. A simple sentence consists of a single independent clause, which has a subject and a predicate, often including a verb and one or more objects. For example, "The cat jumped on the table," is a simple sentence."The cat" is the subject, while the predicate consists of the verb "jumped" and the prepositional phrase "on the table."
A complex sentence has an independent clause, which can act as a simple sentence on its own, and a dependent clause. If this dependent section was placed on its own, it would be a fragment sentence and is not grammatically able to stand alone. An example of this is the sentence "The cat jumped on the table, before she walked in a circle and lay down." In this sentence, the independent clause remains the same as before, but a dependent clause has been added which consists of "before she walked in a circle and lay down."
The other element of a complex-compound sentence that is essential is the "compound" aspect. A compound sentence consists of two or more independent clauses that are combined together. The sentence "The cat jumped onto the table and she began to purr gently," is a compound sentence. Both "the cat jumped onto the table" and "she began to purr gently" are independent clauses and can be used as simple sentences. The word "and" is simply a conjunction that joins the two clauses together, while "before" in the complex sentence above was part of the independent clause.
A complex-compound sentence can then be formed by joining these two elements together, allowing for two or more independent clauses and at least one dependent clause to form a single sentence. This can be created from the previous examples to make, "The cat jumped on the table and she began to purr gently, before she walked in a circle and lay down." The complex-compound sentence here contains one independent clause, "The cat jumped on the table," a second one, "she began to purr gently," and a dependent clause, "before she walked in a circle and lay down."