It is impossible for most people to lick their own elbow. (try it!) 

A crocodile cannot stick its tongue out. 

The “sixth sick sheik’s sixth sheep’s sick” is believed to be the toughest tongue twister in the English language.

The characters Bert and Ernie on Sesame Street were named after Bert the cop and Ernie the taxi driver in Frank Capra’s “It’s a Wonderful Life.”

The longest one-syllable words in the English language are “scraunched” and “strengthened.” Some suggest that “squirreled” could be included, but squirrel is intended to be pronounced as two syllables (squir-rel) according to most dictionaries. “Screeched” and “strengths” are two other long one-syllable words, but they only have 9 letters.