Like a majority of Americans, I speak only one language fluently. C'est la vie.

Sometimes I pretend to be able to muddle along in français (middle school and high school), or español (college). But as cool as it might be to be polylingual, the idea of putting in all the effort required to become fully fluent in another tongue seemed foreign to me (sorry).

Now, a series of studies suggests monolingualism might have held people like me back a bit, and even cost us quite a bit of money.

Below we'll talk first about one of the studies--a British one that's gone viral--along with some American interpretations and adaptations.

From there: an assessment of exactly how much more kids can expect to learn on average, if they acquire the ability to communicate effectively in more than one language. In the final section, you'll find five key language-learning tactics suggested by a top linguistics professor.

Chinese (Mandarin), German ... and French?

We'll start with a recent study by the Centre for Economics and Business Research and Opinion in the United Kingdom. This is actually fueled by a combination of two surveys they did earlier this year, as part of a partnership with the agency behind Heathrow Airport:

First, they surveyed 500 British business leaders, asking them to predict which foreign languages they thought kids should study in order to be more successful and improve their employability.

Second, they interviewed 2,000 British adults who had children under 18 years old, trying to determine how many of their children spoke languages other than English.

Results: About half of British kids are monolingual, with a quarter either not interested in learning new languages or thinking it's too difficult to do so. At the same time however, business leaders predicted that learning another language would be crucial--and advised that kids should be studying Mandarin Chinese, German, and French--in that somewhat surprising order.

Meanwhile, on this side of the Atlantic...

Granted, this is a British study, and I'm going to go out on a limb and suggest that French ranked so high mainly because France is the closest non-English speaking country to the United Kingdom. (Please don't anyone email me about Gaelic. I mean, déanann aon duine airgead ag labhairt Gaeilge," amirite?)

Instead, for American kids, French should be replaced in the top three with Spanish. A majority of people in our hemisphere speak the language natively, and it's actually the second most popular language in the world--behind Mandarin and a bit ahead of English.

Yet, don't get too hung up on which Romance language your kids should study. The bigger point is that they should study a language at all. In the United States, a series of studies reported in 2015 showed that less than 1 percent of Americans are proficient in any foreign language that they studied in the classroom.

This data doesn't include Americans who either immigrated to the United States or who were the children of immigrants, and who grew up with a second language spoken at home. Even including them however, studies cited in The Atlantic show show that only about about a quarter of Americans speak a foreign language at all--and a less than an eighth believe they speak that language "very well."

Total cost or benefit: $67,000 (at least)

The biggest challenges facing American students in the language arena, according to The Atlantic: too little funding and too few language teachers--plus a persistent aversion to broadening horizons as the world changes.

Example: 198,000 American college students studied French in 2013, while only 64 Americans in the entire country studied Bengali. Sixty-four! Set that against the fact that about 75 million people worldwide speak French, while 193 million speak Bengali.

Set the aside however, because it seems skipping out on learning languages hits you in the pocketbook. Researchers at the Wharton School at the University of Pennsylvania and LECG Europe found that adding a second language results in a 2 to 3 percent annual earning bump.

That might not sound like a ton of money, but after the folks behind the Freakonomics podcast threw shade on the economic utility, The Economist analyzed it a bit more deeply. Even an entry level employee who makes only $45,000 per year would see a $900 benefit from having a second language according to the Wharton study. Save that amount, and compound the interest, and you could easily wind up with an extra $67,000 in lifetime earnings.

Plus, I'll just say it: All things being equal, most of us hope our kids make a lot more than $45,000 a year, so the $67,000 figure is probably vastly understated.

How to learn another language

Okay great, but like climbing a mountain or Marine Corps boot camp, learning another tongue often seems like something that people are glad they did only in retrospect. So how do you motivate kids to put extra effort into studying foreign languages?

There are a lot of guides out there, but Dr. Antonella Sorace, a professor of developmental linguistics at Edinburgh University, advised in the materials accompanying the Centre for Economics and Business Research and Opinion study that parents and teachers should follow five top tips as they help students improve foreign language proficiency:

1. Repetition. Also, repetition. "Hearing words and phrases repeated in different ways and in different situations helps children to remember them better and to figure out how the language works," Sorace suggests.

2. Play games. Playing games in a foreign language encourages engagement and makes learning fun. She suggests Pictionary and I Spy, since coming up with the words is part of the game.

3. Travel. Specifically, travel to places where your kids will be forced, or at least heavily encouraged, to speak the languages they're studying. "The more input from native speakers, the better, so holidays are the perfect time to practice," Sorace says.

4. Watch TV. That is, watch TV in the language you're trying to learn. So, telenuevas, I guess--plus this website. Also, music: "Listening to music lyrics teaches children how the language is constructed," Sorace says, "and helps them to develop authentic communication skills."

5. Be positive. I think this could go for anything your kids are trying to learn, but Sorace reminds us that a lot of success comes from attitude. "Positive interest and enthusiasm about the language your child is learning will give them confidence and makes the whole process much more enjoyable," she suggests.