What sound does a duck make?
We imagine that ducks say “quack” just like we imagine that dogs and cats can understand perfect english. In fact, the (human) verbal interpretation of what ducks say is different in different countries, ranging from Portuguese (Qua Qua) to French (Coin Coin) to Turkish (Vak Vak). I always try to determine the ethnicity of the person asking me so that I can respond in a manner familiar to them. Of great help to me in this effort has been the Website of Animal Sounds.