It's a sort of language that we, in Argentina, use to horse around with the people of Rosario
It is something like this:

First, choose a word, e.g: hello
Second, separate the word in syllables (He - llo)
Third, add GAS after the second syllable, in this case, the last one (he - lloGAS)
Fourth, add the 2º syllable's vowel after GAS

The word "Hello" now is "Hellogaso" (hellogasou)
In english, you pronounce the last syllable "gaso" like hello, I mean, "HellogasoU" (you don't write the U, it's just for help).
In the case of words of 3 or more syllables, you can change the second step, e.g: Forward=>Fogasorward

Note: Rosarigasino = Rosarino
Try it! it's difficult but funny XD