The following links will direct you to a large array of tongue twisters you and your students can try. Start with the lower level ones they know from elementary school and then move on to more challenging ones.
Additional Sources [Tongue Twisters and Activities]:
1. https://www.engvid.com/english-resource/50-tongue-twisters-improve-pronunciation/
2. http://busyteacher.org/18835-tongue-twister-lesson-plan-set-of-cards.html
3. http://busyteacher.org/19951-betty-botter-a-visual-tongue-twister-activity.html
Try not to laugh testing out these tongue twisters
Interactive English - Can You Say These Tongue Twisters?
Familiar Tongue Twisters:
• “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”
Try saying it backwards:
“How much chuck would a chuck would wood if a chuck would could wood chuck.”
• Peter Piper picked a peck of pickled peppers
https://www.youtube.com/watch?v=e9QvGVX-gG8
Did Peter Piper pick a peck of pickled peppers?
If Peter Piper picked a peck of pickled peppers,
Where's the peck of pickled peppers Peter Piper picked?
• She sells seashells by the seashore.
The shells she sells are surely seashells.
This is a fun, age appropriate task for 7th grade. Do the first one together and then divide students into pairs or small groups to create their own and present to the class.
Choose a letter of the alphabet – all words will begin with that letter.
EXAMPLE: B
1. Choose a name (Betty)
2. Choose a verb (bought)
3. Choose an adj (beautiful)
4. Choose a noun (bananas)
5. Choose a place (bakery, bar,)
The tongue twister: “Betty bought beautiful bananas in the bakery.”
https://www.teachingenglish.org.uk/article/tongue-twister-game
Competition:
Two students compete who can say it faster without getting their tongue all twisted, or, “Test the Teacher”! We aren’t infallible - tongue twisters are hard for teachers, too. If a teacher feels “brave” enough, they can enter the competition.
Gary Larson's cartoon from The Far Side in 1988 - anotehr Tongue Twister challenge!