I'm going to buy
Voy a comprar un paquete de cigarrillos.
I'm going to buy a pack of cigarettes.
Voy a comprar una caja de cerillas.
I'm going to buy a box of matches.
I'm going to buy a new one.
Me voy a comprar un nuevo saxo.
I'm going to buy myself a new saxophone.
I'm going to buy now.
Voy a comprar la casa de Sang-gu.
I'm going to buy Sang-gu's house.
— A Taxi Driver: Los héroes de Gwangju (2017)
Mañana voy a comprar una camisa.
Tomorrow I'm going to buy a shirt.
I'm going to buy a juice.