I'm going to buy him/her something
He comprado una corbata para Dan y voy a comprarle una bufanda a Elena.
I bought a tie for Dan, and I’m going to buy Elena a scarf.
Voy a comprarle algo de comer.
I'm going to buy him something to eat.
— Deseando amar (2000)
Voy a comprarle unos bollos a Belle.
I'm going to buy Belle some buns.
— Uno de los nuestros (1990)
Voy a comprarle un regalo a Emily.
I'm going to buy Emily a gift.