Here are some links to videos on YouTube by a channel called Wired. I discovered them some time ago but really only started watching them yesterday. They have some pretty interesting videos on languages.
I am sure that there are some GOT’s fans out there, weird has an interesting video by the creator of dorthraki where he speaks about the language and in general how to make your own fictional language.
How to Create a Language: Dothraki Inventor Explains | WIRED - YouTube
Game of Thrones Language Creator Reviews People Speaking Valyrian and Dothraki | Vanity Fair - YouTube
They also have some videos on accents in movies.
Accent Expert Breaks Down 6 Fictional Languages From Film & TV | WIRED - YouTube
Movie Accent Expert Breaks Down 28 More Actors' Accents | WIRED - YouTube
Movie Accent Expert Breaks Down 31 Actors Playing Real People | WIRED - YouTube
Have you ever wondered how translating at international summits and other diplomatic meetings work? Well wonder no more.
Interpreter Breaks Down How Real-Time Translation Works | WIRED - YouTube
Former FBI agent talks about body language.
Former FBI Agent Explains How to Read Body Language | Tradecraft | WIRED - YouTube
Former FBI Agent Breaks Down Gangsters' Body Language | Tradecraft | WIRED - YouTube