In possibly the most bizarre exception in English, the past tense of the verb hang is hung, except when speaking about the method of killing someone--then it's hanged. This, however, is relatively uncommonly used correctly, which, when combined with the slang meaning of the word, a shorter version of well-hung, results in tremendous humor potential. This potential has been most effectively realized, to my knowledge, in Mel Brooks' Blazing Saddles. The main character, Bart, is greeted by his friend Charlie with, "They said you was hung!" "And they was right," is Bart's reply.