These English tongue twisters are great for helping students practice the difference between sounds TH and S:
Six thick thistle sticks. (say it as many times as possible)
Six thick thistle sticks. Six thick thistles stick.
Is this your sister's sixth thistle, sir?
Elizabeth's birthday is on the third Thursday of this month.
This is the sixth zebra snoozing thoroughly.
Nothing is worth thousands of deaths.
The sixth sick sheik's sixth sheep's sick.
A skunk sat on a stump and thunk the stump stunk, but the stump thunk the skunk stunk.