if [someone] comes
Si viene Chernov, se más cortés con él.
If Chernov comes, be more polite to him.
— Cuando pasan las cigüeñas (1957)
If he comes, give him my regards.
Si viene, lo hago a usted responsable.
If you come, I hold you responsible.
Y si viene, no creo que esté contento.
And if he comes, I don't think he'll be happy.
— Reservoir Dogs (1992)
Si viene Bin Laden, dile que estoy en la tienda.
If Bin Laden comes by, tell him I'm at the store.
If he comes, give him this paper.