Before even considering the compound-complex sentence, be sure that you have mastered all of the other sentence types. This is an advanced concept to learn.

The compound-complex sentence uses a coordinating conjunction or a semicolon to join two complex sentences, or one simple sentence and one complex sentence together. Worded, differently, this type of sentence has two independent clauses and one or more dependent clauses.

① The package arrived in the morning, but the courier left before I could check the contents. While Jeff reads books, John reads blogs, but Steph only reads newspapers.

② Sir John A. Macdonald had a serious drinking problem; when sober, however, he could be a formidable foe in the House of Commons.