The word 'Francais' refers to the official language and the people of France. The term comes from the Franks. The Franks were one of the tribes that settled ancient France, when it was called Gaul.
L'exception française. The French exception.The word came round in the middle of the 19th century. It started over a row between France and the U.S.A. The row consisted cultural differences mainly...
"parles-tu français" is certainly very correct, but a bit precious. "Tu parles français" is sometimes deemed not grammatically correct, but the fact is that this is the phrase that a vast majority...