Speakers of Tsimane’, a language used in the Bolivian rainforest, typically use only a handful of color terms, including two—“shandyes” and “yushñus”—that refer interchangeably to anything in the blue-green part of the spectrum. But a study led by Edward Gibson, an MIT professor of brain and cognitive sciences, has found that those who learned Spanish started making more color distinctions than their monolingual peers.

The researchers asked both monolingual and bilingual Tsimane’ speakers to perform two tasks, with the bilingual subjects completing it once in each language. First, they presented 84 color chips and asked people what word they would use for each color. Next, the subjects were shown the entire set of chips and asked to group them by color word.

The researchers found that when working in Spanish, the bilingual Tsimane’ classified colors using Spanish terms. But they were also much more precise about naming colors in their native language. Notably, they used “yushñus” exclusively to describe blue, and “shandyes” exclusively for green.

“Learning a second language enables you to understand these concepts that you didn’t have in your first language,” Gibson says. “The bilingual speakers learn a different way to divide up the color space, which is pretty useful if you’re dealing with the industrialized world.”