What is said to be the toughest tongue twister in English language?

There is no definitive "toughest" tongue twister in the English language, as what is difficult for one person might be easy for another. However, some commonly cited contenders for the title include:

The classic:

* "She sells seashells by the seashore. The shells she sells are seashells, I'm sure. So if she sells seashells on the seashore, then I'm sure she sells seashore shells." This twister tests your ability to differentiate between similar sounds and keep track of the sentence structure.

A challenging one:

* "Peter Piper picked a peck of pickled peppers. If Peter Piper picked a peck of pickled peppers, where's the peck of pickled peppers Peter Piper picked?" The repetition of "p" sounds makes this a real tongue twister.

A humorous option:

* "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." This one relies on contrasting sounds and wordplay.

Ultimately, the toughest tongue twister is the one that you find most difficult to say!