A few really challenging ones… the challenge is to not to see and speak them out, but to remember them and repeat.. keep trying…

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

   
   




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

   
   




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

   
   




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

   
   




5. Imagine an imaginary menagerie manager managing an imaginary menagerie.

   
   




6. The sixth sick sheik's sixth sheep's sick. (This is the World's Hardest Tongue Twister, according the Guiness Book of World Records.)

   
   




7. I am a mother pheasant plucker. I pluck mother pheasants. I am the most pleasant mother pheasant plucker who ever plucked mother pheasants.

   
   




8. She stook on the balcony inexplicably mimicking his hiccuping and amicably welcoming him in.

   
   

And a few more…

1. I'm not the pheasant plucker, I'm the pheasant plucker's mate, And I'm only plucking pheasants 'cause the pheasant plucker's late. I'm not the pheasant plucker, I'm the pheasant plucker's son, And I'm only plucking pheasants till the pheasant pluckers come.

   
   




2. A tutor who tooted the flute Tried to tutor two tooters to toot Said the two to the tutor "Is it tougher to toot Or to tutor two tooters to toot?"

   
   




3. Silly Sally swiftly shooed seven silly sheep. The seven silly sheep Silly Sally shooed Shilly-shallied south. These sheep shouldn't sleep in a shack; Sheep should sleep in a shed.

   
   




4. Three sweet switched Swiss witches Watch three washed Swiss witch Swatch watch switches. Which sweet switched Swiss witch watches Which washed Swiss witch Swatch watch switch?

   
   




5. Theophilus Thadeus Thistledown, The succesful thistle-sifter, While sifting a sieve-full of unsifted thistles, Thrust three thousand thistles through the thick of his thumb.

   
   




6. Now, if Theophilus Thadeus Thistledown, The succesful thistle-sifter, Thrust three thousand thistles through the thick of his thumb, See that thou, while sifting a sieve-full of unsifted thistles, Thrust not three thousand thistles through the thick of thy thumb.