Basically: what was the "international currency" in the Middle Ages?

Pardon the phrasing of this question.

While we all know that the average American sounded indistinguishable from his British counterpart at one point, and the two deviated after their countries were separated, Americans "lost" the "British" accent at different rates depending on the region of the country he was in, and the social stratum he occupied.

I'm asking at around what time the Presidents started sounding 'more American' because that might give a more precise date, and because the President is a symbol of the country and its people in some ways, and the answer to this question would be helpful in identifying some overall, national trends.

I was wondering why some British paratroopers would wear berets while some would wear helmets into combat? (most notably the red berets/red devils). Shouldn't they have been issued the same thing into combat? Also how were the British Paratroopers when compared to the US and German counterparts (airborne and fallschirmjager) throughout the war?

Thanks!

Jewish people are often associated with business and trade. I do not get the sense that Jewish people in the old testament were associated with trade and business to an unusual degree, so at what point did this association begin? I know during the high middle ages, Jewish people played prominent roles as entrepreneurs and moneylenders. Would they have played such a role during the late roman period? How about during the era of the Roman Empire?

I'm wondering this in light of the prevailing stereotype that people living in the United States tend to be monolingual and ignorant of other cultures. By contrast, many people living in Africa, Europe, and Asia grow up speaking three or even more languages fluently.

Well, what about the Native Americans? They were frequently in contact with other tribes, sure. These different tribes probably also spoke different languages. But did that mean they were necessarily multilingual?

Since geography affects the audience you're able to communicate with, I'm guessing that neighboring tribes tended to share linguistic roots and were therefore similar (kind of like Spanish and Portuguese). Were there Native Americans who were in contact with tribes that spoke completely unrelated languages, yet this did not pose a language barrier to either party? Or was one language all you really needed to know to get by in life?

There is strangely little popular media of any kind about the Korean war, and what there is tends to be either contemporary and jingoistic, or extremely broad and highly generalized. I was recently surprised to learn that, during the Chinese counterattack that ejected UN forces from North Korea, significant elements of the American forces and tens of thousands of civilian refugees were surrounded in the port of Hungnam by the Chinese army.

Instead of being captured or destroyed, literally all American forces escaped over the course of a 1-2 week naval evacuation, along with a significant amount of civilian refugees, and all their equipment. The numbers approach those of the battle of Dunkirk in terms of manpower and time pressure (and exceed it in materiel), but the casualties differ wildly: at Hungnam, almost no American casualties are recorded in the writing I can find (2 men were killed and roughly twenty wounded in an accidental explosion).

My question is, why were casualties during this action so light? Were Chinese forces focused on containment, or on pushing towards Seoul? Was the American artillery and air support capable of holding off Chinese forces indefinitely? Were Chinese units under orders to consolidate their position, or wait for reinforcements? It seems to me that, considering the Chinese tactic of mass infantry charges in use at the time, a push through the American artillery curtain wouldn't have been out of the question.

Did Milton attempt to be more accessible? Was that a conscious difference in style?

Or is it just that the English language changed significantly under the affect of the Glorious Revolution?

If so, why did it stop changing (so much) thereafter?

Ockham's razor says that Milton just used to be much more popular and therefore had more influence on what the English language is now. Is that so? If so, why?

Were levies and soldiers ever punished for fleeing the battlefield? Once the enemy stopped pursuing, would people group back together, or just try to find their way home in small groups?

Except for some exceptions (Greek City States, Roman Republic, Italian Republics, etc) and the last 200 years, most humans lived in a monarchy. In Mesopotamia it began with city states but soon they "evolved" into kingdoms. In Egypt you had a king-like Pharao, too. Rome, while first being a republic, became an empire. Most of the medieval world was a monarchy except for the Italian City States. In Asia it was pretty much just monarchies. In South America there had king-like rulers, too.

I could go on and on but my question is why most of humanity for most of its time "choose" to be ruled by 1 guy, a king or emperor or priest or god knows what?

Did that have some kind of big advantage compared to republics or other, non-monarchy governments?

I guess what i'm asking would there be a point that old english speakers wouldn't be able to understand modern english?

I've been finding conflicting sources on manpower needed to sail ships. The common theme seems to be that sources dealing with millitary history always report crews in the upper tens/lower hundreds (70-150 roughly), while accounts on merchant ships report way below that, sometimes even 15 men for a caravel.

What was the criteria upon which the captains decided the amount of crew they hired, if both 150 and 15 men are viable manpower on the same ship?

What else affected the minimum manpower? Did sail type changes, or rigging improvements make bigger reductions? How much impact did the invention of gaff rigging make? Could there have been caravels with front-aft sail plan and outfitted with either a lug or gaff mizzenmast?

I'm confused. I'm a bit of a history buff and have always thought/read that it was a far right ideology but I'm in high school and my history teacher said that the textbook is technically wrong and that Nazism is actually a left wing ideology. He said this candidly as he often goes on long rants that are slightly offtopic. He said he disagrees with the textbook/curriculum because Nazi-style fascism had origins in socialist groups, like the National Socialist German Workers' Party, and that the collectivist and nationalist qualities of fascism move it closer to the domain of socialism or Marxism than liberal democracy (his words).

I did some Googling and while Wikipedia says it's right wing, plenty of other sites say the opposite and reddit is torn on the issue. I thought the internet would solve this but it's just making it worse.