The Mutual Intelligibility series on the Ecolinguist YouTube channel, created by Norbert Wierzbicki, explores how speakers of related languages can understand each other without prior study. Originating from Norbert’s interest in Slavic languages, the series has since expanded to cover a wide range of language families, including Romance, Germanic, Finno-Ugric, and Celtic. The show frequently highlights minority or endangered languages, giving them international visibility and encouraging cultural appreciation.

Each episode features unscripted, real-time conversations between native speakers of different but related languages. The participants are challenged to communicate naturally and see how much they can understand without any prior exposure to the other’s language. For example, one episode pairs a Slovak speaker with a Ukrainian speaker, while others compare Catalan, Spanish, and French; or Dutch and German; or even Welsh and Irish. These spontaneous conversations reveal both striking similarities and surprising misunderstandings in vocabulary, pronunciation, and grammar.

Many episodes have a gamified structure, where guests are scored based on how many words or sentences they correctly guess, or how well they understand stories or instructions. Others include short challenges, such as translating sentences or guessing the meaning of idioms. Some viewers treat it like a quiz show and test their own understanding as they watch.

Despite being a homemade project with minimal production, the series has struck a chord with language lovers around the world. While the Ecolinguist channel as a whole has surpassed 52 million views, the Mutual Intelligibility series remains its most popular, drawing in the majority of that audience with standout titles like:

• “Can Polish and Russian understand Bulgarian?” – 3.6M views

• “Can Polish, Russian and Slovak understand Ukrainian?” – 2M views

• “Can American, Australian, and English speakers understand Old English?” – nearly 2M views

• “Can Germans understand Old English?” – 1.6M views

• “Can Spanish, Portuguese, and Romanian speakers understand Latin?” – 1.57M views
  

Many viewers treat the show as a challenge — testing their own ears and linguistic intuition — while others enjoy it for the lighthearted interactions and cultural insight it provides. The audience ranges from curious monolinguals and heritage speakers to polyglots, educators, and students of linguistics.

Ultimately, the show’s goal is not just to entertain, but to spark curiosity about language relationships, promote linguistic diversity, and encourage learning through play. It reminds viewers that understanding between people doesn’t always require fluency — sometimes, all it takes is an open mind and a shared linguistic root.

Curious what makes the Ecolinguist channel truly stand out?