here is a toughest Chinese tongue twisters四是四,
十是十,
十四是十四,
四十是四十,
四十四只石狮子是死的,
Transliterated in English,Four is four,
Ten is ten,
Fourteen is fourteen,
Forty is forty,
Forty-four stone lions are dead.
BTW, it is known to be the most difficult non-English tongue twister.