Gabi, it´s hard to say. http://www.oxforddictionaries.com/words ... h-language
The Chinese are an example of that.http://www.languagemonitor.com/new-word ... e-1008879/http://www.languagemonitor.com/chinglis ... -language/
Harder still with people going to and fro, everywhere in the world.
Who would think of "mad cow disease" some decades ago? (or BSE, if you wish), words like "delete" (that comes from Latin etimology (same root as "deletrius", although many would think it is a new word).http://en.wiktionary.org/wiki/delete
And words that change their meaning with time, as sinister (that meant "left-handed and "took a turn" to "evil/threatening")http://english.stackexchange.com/questi ... nt-meaning
Or the word that described a person, a count that wouldn´t leave his place for nothing, since he was such inveterate gambler. That was the Earl of Sandwich, John Montagu.http://www.etymonline.com/index.php?term=sandwich
And words that didn´t become popular originally, e.g. "felfie", just didn´t catch on when made it to the social networks in 2010.
It came with a vengeance in 2014, though.http://blog.oxforddictionaries.com/2014 ... he-felfie/
Anyway, words come and go all the time.
Ah, not mention the expressions that come up all the time, the ones that nobody knows where they originated.
To illustrate the point, in America they use to say "the summer/last summer/in the summer of (__the designated year here), instead of a given month. As we say in Portuguese-speaking countries.