was Hänschen nicht lernt, lernt Hans nimmermehr
proverb[vas ˈhɛnsçən nɪçt ˈlɛʁnt lɛʁnt ˈhans ˈnɪmɐmeːɐ̯]
you can't teach an old dog new tricks
was Hänschen nicht lernt, lernt Hans nimmermehr is a German proverb meaning “you can't teach an old dog new tricks”.