They don't. Some Science Fiction writers and film producers have been of UK origin: H.G. Wells, Arthur C. Clark, Gerry Anderson, that might explain it. I think you are probably thinking of the Alien mad scientist (Exeter) from the movie "This Island Earth". It is merely a facade of culture. This is certainly not true of all media space-alien portrayals.
If the nun is British, she probably will have a British accent. If she's German, she'll probably have a German accent.
No one speaks British. They have a British accent.
Rihanna is from Barbados and speaks with a Bajan accent, which is a variant of Caribbean English.
Yes.
I can hear a distinct British accent when you speak.
yes, he has a british accent.
Yes, if you mean English. British does not exist. She does have a British accent also
No, he is Australian, so he has an Austrailian accent. He does speak French, though.
In British English, the term for cousin is the same as in American English. It is simply "cousin."
There is no such thing as a 'British' accent. The accent commonly heard in Harry Potter is the ENGLISH accent. I can see no reason why anyone would stop you from auditioning for a part.
Most people speak with accents, and pirates are just people.
People speak with a British accent in the United Kingdom, which includes England, Scotland, Wales, and Northern Ireland. Additionally, British accents are also found in former British colonies and territories, such as Australia, Canada, and New Zealand.