What is the role of language in empire building?

Question

Consider Romance, Latin, Spanish, Arabic, French, Dutch and English

There is an opinion that languages grow with empire, like Spanish in Latin America or English in North America, most of Asia and Africa and Australia.
So empire and language were complimenting each other.

Answer 1

The more people under a particular government's control, the more that language becomes necessary for the people in the lands control ed. As the power of that empire grows, the more neighboring lands will need to learn that language to engage in commerce and diplomacy with the aforementioned empire.
When you look at Latin, the Roman Empire, and the Roman Catholic church, you see how the influence of the latter two spread the use of the former. When you look at the British Empire and the American world influence, you see how English spread so far. Language does not build empires, empires spread language.

Answer 2

This is an excellent question. Language was a huge problem for the Austro-Hungarian empire which peaked in the 1800s and ended after World War I. Having a common language within an empire was an asset for Rome (Latin) and the Spanish empire in Latin America.
Islamic empires were a bit more complicated. Those under Ottoman rule had to know Arabic and Turkish - or so I have been told by an Algerian friend - yet today Arabic (3.2%) is the 4th most common language spoken in the world following Mandarin Chinese (~14%), Spanish (5%), and English (just under 5% as a primary language). German is 10th (1.5%) with French 18th (1%). [2005 statistics]

Answer 3

Language's role in an empire is to expand the empire verbally and mentally, if it fails physically.

Answer 4

The role of language in any nation is that of national identity.