Ch is a combination of sounds 't' and 'sh'
Materials: Train set
Target: Ch alone
Assist your child in assembling the train tracks, and alternate saying "t" and "shhh" with each piece your place down. Once the track is finished, add the train cars. To make the train go, your child must sound the "t" and "shh", the closer together they say the sounds the faster their train can go!
Target: tʃ in isolation, nonsense syllables
Materials: Train set, mouth model
Show the child where their tongue should be using the mouth model.
Feel the lateral edges of your tongue touching your molars & premolars. Practice saying /t/ and /ʃ/ slowly, gradually voicing more rapidly until they blend into /tʃ/
Incorporate these sounds into a train game. Allow the child to push their train over 1 track piece during the /ʃ/ portion of their phrase. If the child successfully produces this phrase at a quicker pace, encourage them to combine the sounds to /tʃ/ and/or add /u/ to say /tʃu tʃu/ like a train.