The progressive tense indicates an action that is ongoing. It is formed by using estar (in any tense) with a present participle. Present participles are formed by dropping the ending of the verb, and adding the following endings to the stem:
Juan está hablando. Josh is talking.
Estaban cantando. They were singing.
Estuve escribiendo una carta.
A few irregular present participles: poder – pudiendo, dormir – durmiendo, sentir – sintiendo, venir – viniendo, pedir – pidiendo, leer – leyendo, ir – yendo, reír – riendo.
Next: 043 Spanish Haber
Word Document at: 042 Spanish Progressive Tenses