Of preposition and participle

 One for the language fanatics amongst us...

On my 75th birthday, I got a gift certificate from my wife. The
certificate paid for a visit to a medicine man living on a nearby
reservation who was rumoured to have a wonderful cure for erectile
dysfunction. After being persuaded, I drove to the reservation, handed
my ticket to the medicine man and wondered what would happen next.

The old man slowly, methodically produced a potion, handed it to me,
and with a grip on my shoulder, warned, "This is powerful medicine and
it must be respected. You take only a teaspoonful and then say
'1-2-3.' When you do that, you will become more manly than you have
ever been in your life and you can perform as long as you want."

I was encouraged. As I walked away, I turned and asked, "How do I stop
the medicine from working?" "Your partner must say '1-2-3-4,' he
responded. "But when she does, the medicine will not work again until
the next full moon."

I was very eager to see if it worked so I went home, showered, shaved,
took a spoonful of the medicine, and then invited my wife to join me
in the bedroom. When she came in, I took off my clothes and said,
"1-2-3!"

Immediately, I was the manliest of men. My wife was excited and began
throwing off her clothes. And then she asked, "What was the 1-2-3
for?"

And that is why we should never end our sentences with a preposition !
Otherwise you end up with a dangling participle.