I have bought it.
Lo he comprado.
I have not bought it.
No lo he comprado.
Where have you bought it? (Roberto)
¿Dónde lo has comprado?
Where did you buy it?
¿Dónde lo compró?
He has not sold it.
No lo ha vendido.
He would buy it.
Lo compraría.
I wouldn’t buy it.
No lo compraría.
They wouldn’t buy it.
No lo comprarían.
You wouldn’t buy it. (Roberto)
No lo comprarías.
We wouldn’t buy it.
No lo compraríamos.