While many tongue twisters use real words, there are some that are intentionally designed to be nonsensical or use made-up words to make them even more challenging.
For example:
* "She sells seashells by the seashore." uses real words.
* "Peter Piper picked a peck of pickled peppers." also uses real words.
* "Betty Botter bought some butter, but the butter Betty Botter bought was bitter. So Betty Botter bought some better butter to make the bitter butter better." is a bit more complex but still uses real words.
* "The big black bug bit a big black bear, but the big black bear bit back!" is another good example using real words.
But there are also tongue twisters like:
* "Shep, shep, shep, shep, shep." This one uses the same word repeatedly to be tricky.
* "Flibberty gibbet, flibberty gibbet, flibberty gibbet." This one uses made-up words for a purely tongue-twisting effect.
So, the key is that a tongue twister is designed to be difficult to say quickly and clearly. Whether it uses real words, nonsense words, or a combination of both, it's the challenge of articulation that makes it a tongue twister.