A compound-complex sentence combines a compound sentence and a complex sentence.
A complex-compound sentence combines a complex sentence and a compound sentence.
For example, let us consider three sentences as follows:
Cindy was very busy. She finished her assignments. She was late.
Compound sentence
(use coordinating conjunctions)
Cindy was very busy, yet she finished her assignments.
Cindy was very busy, but she finished her assignments.
Cindy was very busy, so she was late.
She was late, but/ yet she finished her assignments.
She finished her assignments, but she was late.
She finished her assignments and she was late.
Complex sentence
(use subordinating conjunctions)
Cindy was very busy; however/ nonetheless/ nevertheless, she finished her assignments.
Cindy was very busy; therefore/ hence/ thus, she was late.
She was late, when she finished her assignments.
She finished her assignments, though/ although/ even though she was late.
Compound-Complex sentence
(use coordinating conjunction first and then use a subordinating conjunction)
Cindy was very busy, but she finished her assignments; however, she was late.
Cindy was very busy and she was late, when she finished her assignments.
Cindy was very busy, but she finished her assignments; therefore/ hence/ thus, she was late.
Cindy was very busy, but/ yet she finished her assignments, though/ although/ even though she was late.
She was late and Cindy was very busy after she finished her assignments.
Complex-Compound sentence
(use subordinating conjunction first and then use a coordinating conjunction)
When she finished her assignments, Cindy was very busy and she was late.
After she finished her assignments, Cindy was very busy but she was late.
Although/ Though/ Even though she was late, Cindy was very busy, but/ yet she finished her assignments.
Since Cindy was very busy, she was late, but/ yet she finished her assignments.
