It is characterized by a large number of words originally borrowed from Swedish, German and Russian, but nowadays chiefly English.
[citation needed] The modern variety has evolved side-by-side with the growing influence of English-language youth subcultures starting from the 1950s.
This brought ever-increasing numbers of new Finnish-speaking working class from around the country to the largely Swedish-speaking city.
Helsinki slang was probably first born in these tightly populated neighbourhoods in their factories, multilingual homes, markets and on their streets.
Some have referred to slangi's roots as a pidgin language or the lingua franca of this multilingual population.
It could be thought as a social language code, by which the multicultural and multilingual working class youth, a speech community, formed their own sociolect.
The initiative for this grew at first from their needs of basic everyday communication, but soon slangi probably came to signify a certain social status as well.
[2] The first known written account in Helsinki slang is from the 1890 short story Hellaassa by young Santeri Ivalo (words that do not exist in, or deviate from, the standard spoken Finnish of its time are in italics): Kun minä eilen illalla palasin labbiksesta, tapasin Aasiksen kohdalla Supiksen, ja niin me laskeusimme tänne Espikselle, jossa oli mahoton hyvä piikis.
Mutta me mentiin Studikselle suoraan Hudista tapaamaan, ja jäimme sinne pariksi tunniksi, kunnes ajoimme Kaisikseen.
The new population was, and continues to be, in greater numbers Finnish-speaking, and the Swedish and Russian influences on the language have declined ever since.
Furthermore, arbitrary modifications are found — these make the resulting slang words alien both to the speakers of regular Finnish and the borrowing language.
For example, Finland Swedish (Sipoo dialect) burk 'cranky' is modified into spurgu 'drunkard', where the added 's' is arbitrary, as is the voicing change of 'k' to 'g'.
As noted above, the language was born north of the Pitkäsilta bridge, but it later spread to the southern neighborhoods as well, including Punavuori (Rööperi in slang).
However, Helsinki slang is always both spoken and written as colloquial Finnish, never as properly grammatical kirjakieli (lit.
Trying to write the above sentence in properly grammatical form like in kirjakieli, to "voitko (sinä) duunata tuon kondikseen?"
Modern Helsinkian Swedish-based slangi is still spoken in the same manner as in Finnish, mixing it into the Swedish language.
Several books and comics have been published written entirely in Helsinki slang, both as translations and as newly authored texts, or something in between.