Sentences complex and compound-complex English Grammar Lessons

A complex sentence,
consists of an independent clause and one or more dependent clauses. An independent clause is a group of words that contains a subject and verb and can stand alone as a complete thought. A dependent clause is a group of words that contains a subject and verb, but cannot stand alone as a complete thought and must be combined with an independent clause to form a complete sentence. Example: Although the cat slept on the couch, the dog chased its tail.
A compound-complex,
sentence consists of two or more independent clauses and at least one dependent clause. Example: Although the cat slept on the couch, the dog chased its tail, and the birds sang outside.

Complex sentences can be used to add detail and nuance to your writing.
Compound-complex sentences can be used to connect a series of related ideas and add variety to your writing.

A sentence with a non-essential clause is a complex sentence with a clause that is not necessary to the meaning of the sentence, but adds additional information. The clause is usually set off by a pair of commas. Example: My sister, who lives in New York, is coming to visit.
A sentence with an appositive is a complex sentence with a noun or noun phrase that renames or explains the noun next to it. The appositive is usually set off by a pair of commas. Example: My sister, a teacher, is coming to visit.

Identify the complex sentence: a) Although the cat slept on the couch, the dog chased its tail. b) The cat slept on the couch, and the dog chased its tail. c) The cat slept on the couch.

Answer: a) Although the cat slept on the couch, the dog chased its tail.

Identify the compound-complex sentence: a) The cat slept on the couch, and the dog chased its tail. b) Although the cat slept on the couch, the dog chased its tail. c) Although the cat slept on the couch, the dog chased its tail, and the birds sang outside.

Answer: c) Although the cat slept on the couch, the dog chased its tail, and the birds sang outside.

Identify the clause in the following sentence: "Although the cat slept on the couch, the dog chased its tail."

Answer: "Although the cat slept on the couch" is the dependent clause, and "the dog chased its tail" is the independent clause.

Rewrite the following compound-complex sentence as a complex sentence: "Although the cat slept on the couch, the dog chased its tail, and the birds sang outside."

Answer: Although the cat slept on the couch and the birds sang outside, the dog chased its tail.

Rewrite the following complex sentence with a non-essential clause as a simple sentence: "My sister, who lives in New York, is coming to visit."

Answer: My sister is coming to visit.