entoncesadverb
Entonces means then, so or in that case in English. It is an adverb.
- then, so, in that case
Entonces mañana le pregunto.
I will ask him tomorrow, then.
Entonces será demasiado tarde.
It'll be too late then.
Entonces tenemos un problema...
So we have a problem...
Entonces decidimos cambiar de plan.
Then we decided to change plans.