This is one of my favorite jokes...
A duck walks into a bar and asks, "Got grapes?"
The bartender, confused, tells the duck that no, his bar doesn't serve grapes. The duck thanks him and leaves.
The next day, the duck returns and asks, "Got grapes?"
Again, the bartender tells him that, no, the bar does not serve grapes, has never served grapes, and, furthermore, will never serve grapes. The duck, a little ruffled, thanks him and leaves.
The next day, the duck returns, but before he can say anything, the bartender begins to yell: "Listen, duck! This is a bar! We do not serve grapes! If you ever ask for grapes again, I will nail your stupid duck beak to the bar!"
The duck looks at the bartender and asks, "Got nails?"
Surprised, the bartender says, “No, we don’t have any nails.”
“Good," the duck says, "Got grapes?”
It's an oldie but a goody.
Enjoy your green beer!