Slang words obey normal Finnish grammar, regardless of their etymology. However, Helsinki slang is always both spoken and written as colloquial Finnish, never as properly grammatical "kirjakieli" (see spoken Finnish). For example, "can you fix that in a working condition?" is ""voitsä duunaa ton kondiksee?"" in slang, where "", "to do, to work" and "", "condition, working order" are slang words. Trying to write the above sentence in properly grammatical form like in kirjakieli, to ""voitko (sinä) duunata tuon kondikseen?"" would be erroneous both in kirjakieli and slang.