The Spanish conditional progressive is very similar to its English counterpart (would be + -ing). In both languages, the conditional progressive expresses an action that would be in progress at a certain point in time. In Spanish, it can also make a conjecture about what might or must be happening.
|Sabía que mis padres estarían comiendo.||I knew my parents would be eating.|
|– ¿Dónde está Lupita?
– Estaría leyendo.
|– Where is Lupita?
– She must be reading.
|Si Juan estuviera aquí, estaríamos estudiando.||If Juan were here, we would be studying.|
The conditional progressive is similar in usage to the conditional, but with an emphasis on the fact that the action would be in progress at the moment in question.