Tongue twisters are saying or phrases which help us learn how to pronounce letter and consonant sounds. By practicing these tongue twisters your spoken English language will improve very quickly. Start with easy tongues twisters and then continue with harder one to help with specific sounds
you will find some of the most popular English tongue twisters. Say them as quickly as you can. If you can
master them, you will be a much more confident speaker

here are three examples

Peter Piper picked a peck of pickled peppers
A peck of pickled peppers Peter Piper picked
If Peter Piper picked a peck of pickled peppers
.Where’s the peck of pickled peppers Peter Piper picked

Betty Botter bought some butter
But she said the butter’s bitter
If I put it in my batter, it will make my batter bitter
But a bit of better butter will make my batter better
So ‘twas better Betty Botter bought a bit of better butter

How much wood would a woodchuck chuck if a woodchuck could chuck wood
He would chuck, he would, as much as he could, and chuck as much wood
As a woodchuck would if a woodchuck could chuck wood

and here is a youtube video explain how to practice those tongue twisters