What is a compound-complex sentence?

A compound-complex sentence is made up of two or more independent clauses and at least one subordinate clause.

Examples

1. Frances Cabrini, who was the first American citizen to be declared a Catholic Saint, was born in Italy, but she became an American in 1909.

Independent clause: Francis Cabrini was born in Italy

Independent clause: she became an American citizen in 1909

Subordinate clause: who was the first American citizen to be declared a Catholic Saint (adjectival clause)

2. She organized some of her sisters into a new order, and they were assigned to work in America by the pope, who was Pius XIII.

Independent clause: She organized some of her sisters into a new order

Independent clause: they were assigned to work in America by the pope

Subordinate clause: who was Pius XIII (adjectival clause)