A sentence or series of words that is hard to say correctly is
called a tongue twister in English. Children love tongue twisters
and challenge their friends to try to say them fast several times
in row. For English learners tongue twisters are a fun way to work
on one or two sounds at a time to get the pronunciation just right.
You should start by saying the tongue twister slowly repeating it
and then building up speed. Try to say the tongue twister a few
times in a row as fast as you can for a bigger challenge. Practice
the following tongue twisters several times a day and see if you
notice any improvement in your pronunciation.