You will see ‘th’ used a lot in written English. In most cases it makes one of 2 sounds: –

/ð/ = voiced dental fricative (the, this, there) /θ/ = voiceless dental fricative (thing, through, throw)

We will practise these ‘th’ sounds by alternating between the two. Make sure you are pronouncing these correctly and train yourself with the th tongue twisters below. As mentioned, these tongue-twisters combine a mixture of the /ð/ (voiced) and /θ/ (voiceless) ‘th’ sounds as well as other similar sounds such as /s/ and /f/.