PORTO, Portugal — Why can’t all countries agree on their currency? Why must travelers take along an MBA or at least a banking expert any time they wish to go beyond San Miguel County, or in our case, the U.S?

We’re preparing for a boat tour of Portugal, the last leg of a trip to Copenhagen where we will visit our son Stan’s family. The tour is a round trip, from Porto, in northern Portugal, back to Porto. It was my friend Pedro Carrico who encouraged me to travel to his homeland.

Pedro, a 2009 graduate of Robertson High School, spent a year in Las Vegas as an exchange student. When he learned of our plans to cross the Atlantic, naturally he wrote, with the hope that his family could meet mine. I brought a copy of a Portuguese-English dictionary, hoping it’ll help.

People who speak Spanish invariably say, “Oh, Portuguese is a piece of cake; if you can speak Spanish, you’ll get along fine in Portugal.” Not quite. Though there are strong similarities between Spanish and Portuguese, the difference — especially with the false cognates — can be glaring.

The toughest thing about learning a language is simply “knowing” that words that look like something in English (or another language) just have to mean the same thing. For example, one of the Spanish words for “pregnant” — embarazada — is taken by many in English to mean “embarrassed.” As a child, I often heard people muttering, “Me da coraje,” which I just assumed had to mean, “It gives me courage.” But the situation in which people used that expression never seemed to fit.

Then I learned that in this context, “it makes me mad” comes closer to the original expression. When Pedro was in the states, patiently he tried to teach me some of the basic expressions and nuances of Portuguese and was polite not to be too critical of my nascent understanding of the language and culture.

Let’s start with money. The Portuguese unit of currency is the Euro, a denomination adopted by some 20 countries, including Spain, France, Germany and Italy. It makes perfect sense; once you learn what it translates to in dollars, you’re set. We got along fine on our trip to Spain in 2002; then, a Euro was worth about one American dollar (the rate today is about $1.27) and most things were conveniently rounded off. Things were simpler then, as burgers, cokes, candy, fruits, bread, etc., generally went for one, two, three or four euros. But a matter of articulation, or lack thereof, almost cost us.

Here’s what happened: My wife had a plate of paella, the national dish of Spain. Instead of being served a steaming plate of spicy chile with a large helping of sopaipillas, we got a mixture of rice, fish, vegetables and even snails. When it came time to pay the bill, the waiter announced it would be “doce euros.”

It sounded like a stutter, as the last syllable of “doce” is similar to the first one in “euros.” So what I heard was “dos euros,” which is close to two American dollars. It took a bit of explaining that the tab actually ran 12 euros, or dollars. And when we’d order sodas in the Plaza Mayor, our tab would be simply dos euros, or two dollars. You see, most of us Americans didn’t enunciate well and often elided the first syllable of “euros,” pronouncing it “yuros.”

Complicating the money exchange in Portugal was the difficulty in getting the money-changers at the Portugal airport to accept American currency. You see, in the states, just about every time someone pays with a new twenty, fifty or hundred bill, the cashier runs a broad marker over it to make sure it isn’t counterfeit. Well, that action makes it “marked money” to the Portuguese, which they won’t accept.

Fortunately, some of our own American dollars were unmarked, and we got enough to manage on. But let’s leave the money and discuss the language.

By far the largest of four vocabularies literate people have is reading. We can take the time to ponder, parse, analyze and look up unfamiliar expressions. For most people, the second largest lexicon is for listening, then writing, then speaking. Given time, I might be able to decipher Portuguese messages, instructions and menus while on this tour.

How will we do when it comes to understanding what the natives say? True, many Portuguese can and will speak English and Spanish for our benefit, but what of the ones who don’t?

On a tour of the Rhine recently, I crammed for finals. I studied German a number of years ago and am currently learning French. So, as our ship reached a city equally divided between the German- and French-speaking natives, I was ready.

At the port cities, as we disembarked to explore the city, we visited a number of stands operated by local venders. I was ready to bargain with them, on their terms. But none of it was necessary. I quickly sensed that their English was better than mine. That happens in tourist towns where there’s considerable linguistic intercourse. And after I’d practiced for so long …

Many Europeans are fluent in two, sometimes three, languages, and the tendency is more apparent where people live close to another country’s border. That makes me wonder about the attitude of many Americans who constantly favor — even demand — a one-language nation. When it comes to arrivals from other lands, typically Mexico, people demand they “learn English or go back where you came from.”

It’s hard to deny the importance of English, not to mention the hurdles you cross by acquiring it. But why do so many remain obstinate when it comes to acquiring Spanish?

Spanish, as an important member of the family of Romance languages, has been around a long time. It would be great if more people embraced it.