Dhaal ذَال
Like 'th' in this: tongue tip between the teeth. One dot above.
Its shapes
Dhaal never joins the letter after it, so it only has two shapes.
Trace it with your finger
👄 Where the sound comes from
The tongue and the front teeth · ذ
The tip of the tongue touches the edge of the top front teeth.
⚖️ Don't mix it up with
- ز
Zaay
Like 'z' in zoo. One dot above. - ظ
Ẓaa · heavy
A heavy 'th' as in this, tongue between the teeth, full mouth.
Say Dhaal and the other letter one after the other, slowly, and feel the difference. A teacher can check you.