The gerund, or present participle, is a special form of a Spanish verb which always ends in -ndo. In English it is translated as the “-ing” form of the verb (for example, “speaking”), which has lead to the frequent mistake of calling this form the “present participle”. The gerund is a verb form which has an adverbial function, not an adjectival function like a participle, nor a noun function like an infinitive.
The present participle (gerund) is formed from the infinitive of a verb by removing the (ar), (er), or (ir) ending and adding (ando) for (ar) verbs, and (iendo) for (er) and (ir) verbs. Please see the examples below.
hablar ---> hablando (speaking)
caminar ---> caminando (walking)
volver ---> volviendo (returning)
comer ---> comiendo (eating)
abrir ---> abriendo (opening)
vivir ---> viviendo (living)
As in English, the present participle can be used in a variety of Spanish sentences.
Yo estoy hablando con mamá.
I am talking to mom.
Ella estaba caminando bajo la lluvia.
She was walking in the rain.
Al parecer, Bryan Danielson estaría volviendo pronto a WWE.
Apparently, Bryan Danielson would soon be returning to the WWE.
Ellos estaban abriendo los regalos cuando llegamos.
They were opening the presents when we arrived.