Shibboleth - What’s that? That sounds so strange!
Indeed, it’s a strange word. But we are faced with Shibboleths almost every day. Shibboleth is a certain word, phrase or sound, whose pronunciation or use distinguishes native speakers from different cities or regions within a country.
In reality, it’s quite easy to distinguish between an American English speaker and a British English speaker. While in America, people say “truck”, British people would rather use the word “lorry”.
Also in Germany we can easily identify people from Berlin. It’s because they often struggle with the correct use of Akkusativ and Dativ and tend to use Dativ “dir” where it’s not correct (“Ick höre dir!” 
)
Here in Ecuador a Shibboleth to easily identify people from the Central Mountains, especially native Quichua speakers, because they usually don’t roll the “r”, a very rare exception among Spanish speakers. 
What Shibboleths do you have in your language? 
PD: The word “Shibboleth” itself is Hebrew and means “flood, torrent” and comes from a story in the Bible. This word was used as a password in a civil war to clearly identify people from one of the tribes because they didn’t pronounce it correctly. In times of war (even in modern times), a Shibboleth was often used to uncover spies or enemies 
No one outside of the area knows what we’re talking about. A Nottingham spy would quickly give themselves away by ordering a bacon and egg cob 
. There is a word we all say different in most parts of Colombia and its pen. I’m from Bogotá, so I say “esfero” 
, but in other parts they call it “pluma”, “boli”, “lapicero” and more. Definitely a common word that has lot of names.
