English Tounge Twisters

Here are some cool English Tongue Twisters, have fun !
                   Repeat them a few times !
                   -A good cook could cook as much cookies as a good cook who
                   could cook cookies
                   -Betty Botter bought some butter, but she said "this butter's
                   bitter! But a bit of better butter will but make my butter
                   better" So she bought some better butter, better than the
                   bitter butter, and it made her butter better so 'twas better
                   Betty Botter bought a bit of better butter!
                   -Black bug bit a big black bear. But where is the big black
                   bear that the big black bug bit?
                   -If you understand, say "understand".
                   If you don't understand, say "don't understand".
                   But if you understand and say "don't understand".
                   How do I understand that you understand? Understand
                   -I thought, I thought of thinking of thanking you.
                   -RED BULB BLUE BULB RED BULB BLUE BULB
                   -I wish to wish the wish you wish to wish, but if you wish the
                   wish the witch wishes, I won't wish the wish you wish to wish.
                   -Sanjeev's sixth sheep is sick
                   -A sailor went to sea To see, what he could see. And all he
                   could see Was sea, sea, sea.
                   -Upper roller lower roller Upper roller lower roller
                   -If two witches were watching two watches, which witch would
                   watch which watch? .
                   -Six slippery snails, slid slowly seaward.
                   -I scream, you scream, we all scream for ice cream
                   -She sells seashells by the seashore.