Here you will find practice words, phrases, sentences, and paragraphs for both voiced "th" (and in "there") and voiceless "th" (as in "three"). Most of these are taken from Home Speech Home. A common prompt or reminder for children and students working on "th" is to simply say, "Keep your tongue on your teeth". This sound is a very visible sound, meaning that kids learn it a lot easier if they see someone produce it correctly and then watch themselves produce it. So don't be afraid to get out the mirror (or go to the bathroom to practice the words).
https://www.youtube.com/watch?v=z7BVQicWaOA
"Th" Picture Words Initial "th" Pictures
Voiceless "th" Word Lists Initial voiceless "th"
Voiced "th" Word Lists Initial voiced "th"
Voiceless "th" Phrases Initial voiceless "th"
Voiced "th" Phrases Initial voiced "th"
Voiceless "th" Sentences Initial voiceless "th"
Voiced "th" Sentences Initial voiced "th"
Tongue Twisters The thirty-three thieves thought that they thrilled the throne throughout Thursday. I thought a though, but the though I thought wasn't the thought I thought I thought. If the thought I thought I thought had been the though I thought, I wouldn't have thought I thought. Something in a thirty-acre thermal thicket of thorns and thistles thumped and thundered threatening the three-D thoughts of Matthew the thug – although, theatrically, it was only the thirteen-thousand thistles and thorns through the underneath of his thigh that the thirty-year-old thug thought of that morning. Thirty-three thousand feathers on a thrushes throat
https://www.youtube.com/watch?v=SVOnAI8ktKY