Forty-one language groups have difficulty with this sound in English! Here are some minimal pairs that show th versus t. Other alternate pronunciations may be used by your learner for the th sound.
thank
thorn
three
thought
tenths
fourths
deaths
myths
math
both
broth
wrath
tank
torn
tree
taught
tents
forts
debts
mitts
mat
boat
brought
rat
Sentences
Note: It is not always possible to construct sentences meaningful to the learner when working with minimal pairs.
Lawson, V. K. (1995). English as a Second Language trainer’s guide: 18-hour core tutor training. Syracuse, New York: New Reader’s Press, a division of ProLiteracy Worldwide. ISBN 0-930713-74-5.
Handout 12.8