Twist the tongue -7-

While these are the hardest tongue twister phrases;

A big bug bit a bold bald bear and the bold bald bear bled blood badly.

  

Brisk brave brigadiers brandished broad bright blades, blunderbusses, and bludgeons -- Balancing them badly. 

Can you can a canned can into an uncanned can like a canner can can a canned can into an uncanned can?

  

If you must cross a course cross cow across a crowded cow crossing, cross the cross coarse cow across the crowded cow crossing carefully.

  

Imagine an imaginary menagerie manager managing an imaginary menagerie. 

The sixth sick sheik's sixth sheep's sick.

*According to the Guiness Book of World Records, This is the World's Hardest Tongue Twister

Source : American Folklore

P/S : can't even pronounce 'em properly.. haiyah!