Why add "de" after " voy a + infinitive,"

Question

I don't understand this structure. Please help out. Why is "de," added after " voy a +inf"?

Silvia Píriz · Accepted Answer

Hola Engel A.
Could you please share the full sentence where you’re seeing “voy a + infinitivo” + “de”? This will help us understand exactly what structure you’re referring to, as “ir a + infinitivo” doesn’t normally take “de”.
Looking forward to your example so we can clarify it for you!
Saludos
Silvia

Clara Melchor Bowman · Answer

Buenas Silvia,

Me parece que Engel se refiere a las frases/ la construcción idiomatica que usa 'Ir de + noun'

Ir de vacaciones

Ir de compras

Ir de viaje

Hay un ejemplo arriba:

Tú vas a ir de vacaciones el viernes.