How do you cast spells in Harry Potter 5 on the ds?

1. Equip your wand. To do this, open your inventory and select the "Wand" item. Then, press the "A" button to equip it.

2. Select your spell. To do this, press the "L" or "R" buttons to cycle through the available spells. The spells you have learned will be highlighted.

3. Aim your wand. Once you have selected your spell, aim your wand at your target by moving the stylus on the touchscreen.

4. Cast your spell. To cast a spell, press and hold the "A" button. The longer you hold the button, the more powerful the spell will be.

5. Release the "A" button. When you are finished casting your spell, release the "A" button. Your spell will be cast, and your target will be hit.