"An Irishman walking through a field sees a man drinking water from a pool with his hand.
The Irishman shouts "Na ol an t-uisce, ta sé lan de chac bo" (Don't drink the water, it's full of cowshit.)
The man shouts back "I'm English, speak English, I don't understand you". The Irishman shouts back "Use both hands, you'll get more in."