A New Yorker who has learned dozens of languages left Cardiff locals stunned after speaking to them in Welsh.

Arieh Smith, 33, known as Xiaomanyc online, spent three weeks studying Welsh before flying across the Atlantic to chat with native speakers.

He has amassed more than a billion views on YouTube documenting himself speaking languages across the globe.

"[Welsh] is definitely one of the most beautiful languages I've ever had the pleasure of studying," said Arieh.

Arieh, who said he was never very good at languages in school, started to learn Mandarin after leaving high school by immersing himself in Chinese media, before moving to Beijing.

"It really opened my eyes to the idea that it is actually possible to learn languages to fluency as an adult," he said.

After studying more than 50 languages from across the world, and travelling to many of them to speak with locals, he turned his attention to Welsh.

"I've been wanting to study the Welsh language for a while… I get comments all the time from people all over the world who want me to learn their language, and then come to their country," he said.

"Welsh to me was very exciting because, as an American, I don't think we typically think of the UK as being a country that, in addition to English, is full of other languages that people have been speaking for thousands of years."

It takes Arieh about 15 sessions with an online tutor before he is confident enough in his abilities to make a trip to a country.

Which, in this case, involved learning from "both a native Welsh speaker, but also from a German man who has been living in Wales for a while".

"I would say Welsh is definitely in the upper quartile in terms of difficulty, so quite hard. At the same time, it's a beautiful language," he said.

Arieh, who picked Cardiff due to ease of flying over from New York for just a few days of filming, said he did have concerns about finding enough Welsh speakers in the capital.

"I had heard from my contacts and teachers that one very clear message was 'do not come to Cardiff to speak Welsh', like that is not the place you want to go to," he said.

"I ended up finding a lot of people in Cardiff who spoke Welsh, which was really cool and it was a beautiful city."

Arieh said speaking Welsh, as a New Yorker, to people in Cardiff brought about a "mix of reactions".

"There was one category of reactions that was like, just complete confusion, like 'who is this foreigner? And what language is he speaking with me?'.

"But then, I would say with most people, if I pressed on and kept speaking Welsh, at some point the light would go on their head and be like 'oh, dwi'n siarad Cymraeg - you're speaking Welsh?'. So that was really cool.

"The other category of reaction was just instantly like, 'oh [damn], you're speaking Welsh, that's great'.

"And I encountered quite a few native or fluent speakers in Cardiff and we had some great conversations and in Welsh, which was really fun and interesting."

Arieh hopes the content he creates online will help inspire people to pick up Welsh, or any other language they want to learn.

"Learning a language to fluency as an adult is totally possible... it's changed my life and I think that it can change your life too."