Why do they use a plural form of "armies" in these two? I think "army" is sufficient to denote the meaning, but does the plural form have any real plural meanings like multiple armies combining many regiments, batallions, etc?
ex1) Before the year of 1500, the Mayas, Aztecs, and Incas were three great civilizations in Mexico and South America. All three were defeated by Spanish armies,but some historians say that with the armies came an even more horrifying weapon : small pox.
ex2)... One famous example is Napoleon's invasion of Russia. At the time, many people thought he was going to conquer all of Europe. But he sent his armies into Russia during the winter, and they were defeated because of the severe cold....
[not at teacher]
How do you explain the second example?
Also, related? There are a few English words that are plural on their face, but occationally require the plural form:ex2)... One famous example is Napoleon's invasion of Russia.
monies
peoples
fishes
fruits
As a native speaker, I usually know when these should be used, but without thinking hard about it now, I really don't know the usage rule(s) offhand...
I can't explain the Napoleon example. There, I would have used "army".
I would have also used "army". Perhaps "armies" sounds more intimidating? He sent a horde, vs. he sent hordes?
United States Army - Wikipedia, the free encyclopedia
See the US Army, for example. While the term in the singular collectively refers to all of the ground-based fighting forces, the "army" is itself divided into divisions which are also called "armies." For example, US Third Army, US Army Africa, US Army Pacific.
So it's entirely possible that Napoleon had different subdivisions of his forces, each which was known as an army, and together these armies went to Russia.
Napoleon's troops were divided into separate armies. Look here: Napoleon Bonaparte's Army : Napoleonic Wars : Napoleon Bonaparte :