The relatively sparse population density of Helsinki and its peculiar structure have often been attributed to the lateness of its growth.
Helsinki is used to refer to the city in most languages, but not in Swedish.
The Swedish name Helsingfors is the original official name of the city of Helsinki (in the very beginning, spelled Hellssingeforss). The Finnish language form of the name probably originates from Helsinga and similar names used for the river that is currently known as the Vantaa River as documented already in the 14th century. Helsingfors comes from the name of the surrounding parish, Helsinge (source for Finnish Helsinki) and the rapids (Swedish: fors), which flowed through the original village.
Another suggestion is that the name Helsinge may have originated with medieval Swedish settlers who came from Hälsingland in Sweden. Others have proposed that the name derives from the Swedish word hals (neck), referring to the narrowest part of the river, i.e. the rapids.
In Helsinki slang the city is nicknamed as either Stadi (from the Swedish word stad, meaning "city") or Hesa (short of Helsinki + slang suffix sa), with Stadi being used to assert that the speaker is native to the city. Helsset is the Northern Saami name of Helsinki
