Simple Conditional Progressive
The Spanish Simple Conditional tense can also be progressive and express hypothetical situations in the past or in the present, seen as continuous possible actions: "something that would (not) be happening". For example:
Yo estaría saltando de alegría si me hubiera pasado eso a mí.
I would be bursting with joy if that had happened to me.
Si yo fuera él, estaría planeando mi huida.
If I were him, I would be planning my escape.
¿Qué estarían haciendo esos chicos tan tarde en la calle?
[I wonder] what those boys could be doing outside so late [at night]?