Forming it
Estar conjugated + verb stem (infinitive without the ar/er/ir) + present participle
Regular ar present participles
-ando
Regular er/ir present participles
-iendo
Ir present participle
Yendo
Verbs with two ‘e’s in them (creer, leer etc.)
-yendo
Traer
Trayendo
Caer
Cayendo
Contribuir
Contribuyendo
Incluir
Incluyendo
Oír
Oyendo
If a stem ends with ‘ll’ or ‘ñ’ t
-endo
Any ir verb with a stem change in the third person preterite (e-i or o-u) as well as poder
Will have the same stem change in the present participle ending