“Quack”读作/kwæk/，最常指鸭子那标志性的“呱呱”叫声，比如我们可以说：“The little ducklings quack loudly as they follow their mother to the pond.”（小鸭子们跟着妈妈往池塘走时，呱呱叫得响亮。）

“Quail”这个词也很有意思，它既指“鹌鹑”——一种体型小巧、常被捕猎的鸟类，也有“胆怯、畏缩”的意思。比如描述鹌鹑时可以说：“A quail scurried into the grass when it heard the footsteps.”（一只鹌鹑听到脚步声，赶紧窜进了草丛里。）而用它表示“胆怯”时，可这样用：“He quailed at the thought of having to speak in front of a large crowd.”（一想到要在一大群人面前讲话，他就胆怯了。）