Breakdown of Después de que os vayáis, limpiaré la casa.
la casa
the house / home (also "at home")
os
to you (plural) / yourselves
limpiar
to clean
irse
to leave, to go away
Questions & Answers about Después de que os vayáis, limpiaré la casa.
Why is vayáis in the subjunctive here?
In Spanish, time expressions like después de que require the subjunctive when they refer to an action in the future. Since "you guys leaving" hasn't happened yet at the moment of speaking, we must use the subjunctive form vayáis.
Why is there an os in front of vayáis?
The verb used here is irse (to leave or go away), not just ir (to go). While ir usually focuses on the destination you are heading to, the reflexive verb irse focuses on the act of leaving a place. The os is the required reflexive pronoun for the vosotros (plural "you" in Spain) form.
Why do we need the word que in después de que?
You must use que because it introduces a clause with a conjugated verb (vayáis). If the person leaving and the person cleaning were exactly the same, you could drop the que and just use an infinitive verb, such as después de salir, limpiaré la casa (After leaving, I will clean the house).
Could I say voy a limpiar instead of limpiaré?
Yes, they mean almost exactly the same thing. Limpiaré is the simple future tense (I will clean), while voy a limpiar means "I am going to clean." In everyday spoken Spanish, both are perfectly natural and you will hear them used interchangeably for future plans.