Mark Zuckerberg did a public Q&A session today — in Mandarin Chinese. Yes, the Facebook CEO set out to learn the (very difficult) language in 2010, in his spare time.

“On Wednesday I did my first ever public Q&A in Chinese at Tsinghua University in Beijing!” Zuckerberg wrote on Facebook after the event. “We discussed connecting the world, Internet.org, innovation, and the early days of Facebook.”

Zuckerberg barely uttered a single word in English — just one quick “I’m sorry,” when he misspoke.

After the CEO gave a short answer to the first question, loud applause, laughter, and a couple of gasps could be heard from the audience.

He made convincing inflections. He made jokes. He seemed totally relaxed.

Here’s the first part of the Q&A:

You can find the full video here.