The language's history can generally be divided into the 'old' slang () and the 'new' or 'modern' slang (). Old slang was common in Helsinki up to the mid-20th century, and is thicker and harder to understand for an outsider of the group, even to one who would be capable in modern slang, because it incorporates a far greater number of Swedish and Russian loan-words than the modern variation. Old slang is mostly spoken by older Helsinkians, many of whom consider it the only true slang.