Tongue Twisters - Ugh! How difficult They Are!

A tongue twister is defined as a phrase or sentence that is hard to speak quickly fast. You are supposed to reapeat it quickly several times in quick succession.

Last night, I was looking for some Czech tongue twisters for my friends who are studying Czech.  and who I would like to "test" and give us a good make them (and me) laugh. I found a special dedicated website where there are more than 3,500 tongue twisters in 118 languages. I was curious what tongue twisters were listed in Czech. I saw 154 examples. I enjoyed reading them and trying to say them properly.

If you are interested, you can find a list of tongue twisters in your native language.
http://www.uebersetzung.at/twister/index.htm

I know a few English tongue twisters. I am not good at saying repeating them in rapid succession fast. What about you? How do you fare with this one? Can you say this tongue twister below quickly? [This is not wrong but using the same old thing makes your writing dull. BTW, thanks for the link]

She sells sea-shells on the sea-shore.
The shells she sells are sea-shells, I'm sure.
For if she sells sea-shells on the sea-shore
Then I'm sure she sells sea-shore shells.