Put your hand in front of your mouth to feel the "t" sound burst of air. Touch your throat to feel the difference in vibration for these two sounds (voiced and unvoiced).
Touch your bottom teeth with the tip of your tongue. The sides of your tongue will touch your back teeth. Blow out air continuously.
Touch your bottom teeth with the tip of your tongue. The sides of your tongue will touch your back teeth. Blow out air continuously while using your voice.
The "s" sound
The "s" sound
The "z" sound
The "z" sound