To speak Norwegian
Katsoa ihan ruotsiksi
To look at in all Swedish (way)
To look at someone cross-eyed. Perhaps originates from the times when Sweden still had left-handed traffic?
Nälkä kuin Viron sudella
Hungry like a wolf in Estonia
Someone’s really hungry. In Finland werewolves were called vironsusi (Estonian wolf). In old stories werewolves were usually Estonians… they transformed usually during the weddings… who knows why. So, hungry like a werewolf
To speak pig’s German
It means that somebody is speaking something completly weird or in not understandable language.
To fuck up (really badly)
Derived from ‘ryssä’ which is a derogative term for a Russian, literally: to do (as) a Russki.
Kiroilee kuin Turkkilainen
To curse like a Turk
Someone is a real badmouth. Perhaps goes back to 19th cent. and Ottoman wars?