ITHACA, N.Y. — Danilo Moreta, a Cornell University graduate student studying corn breeding, stood wearing jeans and a black shirt as undergraduate students entered Room 336 in the Plant Science Building for a Tuesday night section of “PLSCI 4300, Applications in Molecular Diagnostics.”

“Hola. Cómo estás? Bien?” he offered to students taking seats. Moreta teaches the science section in Spanish.

Partly, that’s because students in January will do fieldwork in Chilean vineyards, gathering leaf samples to test for viruses. They will need to query lab workers about such things as where to find a micropipette — “Me puedes ayudar a encontrar una micropipeta?” — said Moreta, who was raised in Colombia and honed his English in school and through rock lyrics (Bon Jovi, Guns N’ Roses, the Doors).

But the Spanish section also reflects a move at Cornell and more than two dozen other campuses to combat the notion that language-learning belongs only in language classes.

Why not discuss Southeast Asian politics in Indonesian? Opera in Italian? Shouldn’t Cornell Law students who are helping to represent Hispanic death-row inmates talk about the law in Spanish? At Duke, why not probe the racial, power and political dynamics of soccer in French, Italian or Portuguese?

The move to add language-specific sections to courses allows students to keep up their skills in a second language without enrolling in a full-credit, time-consuming course. The sections can also help students acquire basic second-language vocabulary useful in their primary academic fields.

While not a new idea, second-language sections are “seeing a resurgence of interest,” said Deborah Reisinger, director of Cultures and Languages Across the Curriculum at Duke, which offers eight to 10 such courses a year (including “Soccer Politics”), in languages ranging from Arabic to Hindi, Portuguese to Swahili.

Traditional language-learning in the United States is in trouble. Is this approach an answer?

“Most kids don’t want to become a linguist or get a PhD in the language, but they do want to speak,” Reisinger said. Language-learning, she said, is easily applied “to content in other fields — global health, environmental studies, public policy.”

Americans have a puzzling relationship with second-language learning, at a time when the nation is increasingly diverse. In 85 cities, most residents speak a language other than English at home. Only 10 percent of U.S. English speakers are proficient in a second language. And few learned one in school.

One signal of a quality high school is how many languages it offers (and which ones). The number of students taking Advanced Placement tests in Chinese, French, German, Italian, Japanese or Spanish rose 68 percent between 2008 and 2018. Yet college language-course enrollment is plummeting.

The Modern Language Association reported a 9.2 percent drop in college language-class enrollment and a 5.3 percent decline in course offerings between 2013 and 2016. Enrollment is down 15 percent since 2009 — even though more students want global experiences, including international internships and study abroad, and a chance to practice languages they do speak.

“I don’t understand the conceptual model for global competence that leaves language out,” said Dianna L. Murphy, director of the Language Institute at the University of Wisconsin.

Baffled by declining enrollment, Murphy plans to survey students about their attitudes toward language-learning. She wants to know “the extent to which students see language-learning as linked to future careers.” Recent surveys show that employers need multilingual workers.

But on many campuses, learning a second language is treated simply as a box to check — and that means testing out of the classes or figuring out how to most easily meet requirements. At the University of Utah, those at a certain proficiency level can purchase the language credits they need for graduation; some colleges have dropped language requirements altogether. And language courses are often seen as rote, focusing only on grammar and vocabulary memorization, said Reisinger. Yet, she said, “when I teach third-semester French, I talk about immigration issues.”

Another problem, said Howie Berman, executive director of the American Council on the Teaching of Foreign Languages, is that upper-level language classes focus on reading literature, when students “want to fix the world’s problems.” Language-learning, said Berman, “needs to be more relevant.”

While science, technology and engineering classes are celebrated for teaching real-world skills, language classes are not, language educators lament. “It is treated as this extra piece that is not a central part of education,” said Amanda Seewald, president-elect of the Joint National Committee for Languages and the National Council for Languages and International Studies, a legislative advocacy group.

Research shows links between language-learning and other life benefits — more-flexible thinking, greater empathy, protection against age-related cognitive decline — although findings are hardly robust.

For many, the case for language-learning is simply about being able to interact with people from other cultures. In some academic fields, research is going global. Jeremy Thompson, the Cornell professor teaching “Applications in Molecular Diagnostics,” requires that students take a Spanish section — Moreta’s, or one for beginners. The course can’t solely focus on science, he said, if students are going to work with lab techs and peers in Chile.

Yet students often view language courses as an onerous commitment, said Lisa J. Sansoucy, coordinator of language-learning initiatives at Cornell. “Students say it is a lot of credit. It is a lot of time. It is every day.”

That is one reason Sansoucy has worked to increase language sections in mostly English-taught courses (Cornell has offered 62 since the program started in 2016, mostly taught by multilingual graduate students). She said students like that they meet just once a week.

Abigail Reing, a sophomore at Cornell majoring in food science, took Thompson’s course because of the Spanish component (she’d studied the language in high school). Her major has so many requirements that “my schedule is pretty packed through the four years,” she said. “I can’t take a five-credit Spanish class that meets every day.”

That is also true for Maya Wilson, a senior majoring in biology with plans for a career in medical research. Moreta’s section, she said, “gives me a chance to revisit my Spanish,” which she studied in high school.

In 2015, Stephen Angle, director of the Fries Center for Global Studies at Wesleyan University, grew alarmed when he saw language enrollments had dropped 11 percent from the previous year. The decline coincided with a policy that let students pick courses online over the summer. Suddenly, students were not meeting with adviserswho might have suggested they study a language. And administrative messages “said nothing about languages,” Angle said.

“Nobody was against languages. But nobody was paying attention to the importance of languages.”

Angle and his colleagues responded with a language campaign, including what he called “relentless interface with admissions and the dean’s office.” They combed website FAQ’s, and wherever they saw a spot for a video or fact promoting language study, they added one. They created a “language registry” to alert students, staff and faculty when an event was scheduled in their target language.

And last spring, they tried something new: offering second-language sections for three courses taught in English. This fall, there are five such language sections at Wesleyan. Angle, who teaches Classical Chinese Philosophy in English, does one in Mandarin.

At the first section meeting in early September, 16 students — heritage speakers and language learners — chattered in Chinese and English as they crowded into a seminar room. Angle toggled between English and the staccato rhythm of Mandarin, noting that in the “Analects of Confucius,” “there are three different words that we translate as ‘virtue.’ ”

For Xiangyi Guo (she goes by Phyllis), a junior from Beijing who went to high school near London, the section is both a treat (Chinese is her native language) and a challenge. “I haven’t had any academic experience in Chinese,” she said, adding that she started learning English “when I was 5 or 6.”

But Guo wanted to tackle Chinese philosophy in Chinese. “Language,” she said, “can make a real difference in how you understand things.”

This story about second-language learning was produced by the Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education. Sign up for the Hechinger newsletter.