The 'tʃ' sound in English is known as the voiceless alveo-palatal affricate. Here's a step-by-step guide on how to produce this sound:
Position your tongue: Place the tip of your tongue against the alveolar ridge, which is the ridge behind your upper teeth.
Make a stop: Briefly stop the airflow by pressing the tip of your tongue against the alveolar ridge.
Release into a fricative: Without completely removing the tongue from the alveolar ridge, create a small gap for the air to pass through. As the air flows, create friction by narrowing the space between the tongue and the hard palate, which is the roof of your mouth.
Pronounce the sound: Release the airflow while maintaining the friction, creating the 'tʃ' sound. The sound is similar to the 'ch' sound in words like "cheese" or "champion."
It may take some practice to master this sound, as it involves coordination between the tongue, teeth, and airflow. You can try listening to native English speakers or watching instructional videos to get a better understanding of the precise articulation.